For two years the Alameda County (Calif.) Sheriff's Department has organized and hosted Urban Shield, the nation's largest SWAT exercise. The 48-hour competition involves 25 tactical teams working 24 realistic scenarios. This year's event was held Sept. 12-15, and POLICE editor David Griffith was on the scene.

7:30 a.m.: Breakfast Talk

"It's the best training you can get anywhere. Period," the SWAT team leader says as he sips his coffee. "There's just nothing like it."

I scratch down his comments after agreeing not to identify his team. Then I mull what he has just said. I write the following question in my notes: "What makes Urban Shield so great?"

ORIENTATION DAY

The participants-eight officers per team-are gathered in a large classroom at the Alameda County Emergency Operations Center for orientation and medical and safety briefings.

Among other things, they learn that no live weapons or live ammo will be allowed in the scenario areas. They will use only weapons issued at the site that have been modified to fire Simunition FX marking cartridges. They are also warned about dehydration and other medical concerns.

The briefings complete, Commander Charles Nice of the Alameda County SD dismisses the teams: "Go get some rest," he says. "Once I give the command at 6 a.m., we are going for 48 hours."

Each team will start tomorrow morning at a different scenario and each is expected to complete all 24 scenarios, including a grueling 13-mile trail run, without more than a few catnaps of sleep.

The next two days are going to be hell for these teams, I think to myself.

Looking at the schedule, I take special note of which team has been randomly selected for the last 13-mile run. The Lawrence Livermore National Laboratory Special Response Team will hit the trail in the wee hours of Monday morning after nearly 48 hours of constant work. Poor bastards.

DAY ONE

10:45 a.m.: Caldecott Tunnel

Some five hours ago, all (simulated) hell broke loose in the Bay Area. Terrorists of all stripes have executed plans to attack nuclear facilities, sabotage oil refineries, kill dignitaries, and take hostages across three Bay Area counties. It's up to the 25 tactical teams participating in Urban Shield to stop them.

An FBI SWAT team from the San Francisco office is preparing to tackle Scenario #5, an attempted terror attack on the Caldecott Tunnel.

The Caldecott Tunnel connects Oakland with the outlying communities in Contra Costa County. It is a major concern for counter-terrorism planners in the Bay Area.

Scenario #5 is based on that concern. Teams are told that terrorists have entered the tunnel with explosives and automatic weapons. Their mission is to stop the terrorists from bringing the tunnel down onto the weekend traffic whizzing by below.

The San Francisco-based FBI team has probably gamed this scenario before . But that won't make it easy. The tunnel is a nasty place for SWAT operations. It's dark, traffic noise drowns out communications, and there are drops of up to 10 feet.

Safety officers check the FBI guys for live weapons; they are briefed on the situation. Then they gear up and go in.

1:45 p.m.: Oakland International Airport

Inside the stuffy confines of an old FedEx cargo jet, I am waiting for a battle. Outside, the Oakland Police Department SWAT team is preparing its assault.

In Scenario #18, Aircraft Interdiction, suspected terrorists have taken over the plane and taken the crew hostage. The team has to take the aircraft back and rescue the hostages using a variety of tools, including a massive Blackwater Grizzly MRAP armored vehicle.

The retired tactical officer portraying the lead "terrorist" gives everyone the cue: "The Grizzly's moving. Get ready."

He goes back out and cracks off a few blank rounds from a revolver, then he comes charging back onto the plane issuing orders to his fellow terrorists. "Back door. Back door," he barks and picks up a Sim modified MP5.

Oakland SWAT storms the plane, and an intense firefight begins. Casings clink off the metal. Sim rounds splat against the bulkhead and bags of gear.

Seconds later the battle is over.

As the Oakland team moves on to its next scenario, its leader Sgt. Mike Gonzales chats with the press. "We could all use more training like this," he says. "It was extremely stressful, extremely reality-based."

3:25 p.m.: Glenn Dyer Jail

Situated in downtown Oakland, Glenn Dyer jail consists of two buildings; one stands six stories, the other four. For Scenario #14, officers were required to run a half mile with gear to the building then up 18 flights of stairs to the roof.

And that's where the fun really began. The teams had to get from the roof of the six-story building to the roof of the four-story building across the courtyard via a 170-foot-long zip line.

Once they reached the roof of the other building and disengaged from the zip line, officers were paired off, given BeamHit-equipped pistols, and told to engage targets on the roof.

I follow behind Officer Ken Nelson and Officer Jason Grimm of the California Highway Patrol SWAT team as they work the BeamHit drill. They move quickly and smoothly to clear each room, slicing the pie and going high-low to take out the targets.

"It was awesome, just like a video game for adults," Nelson says afterward. "It was a good training scenario," adds Grimm.

And it hasn't ended. Nelson and Grimm will wait for the rest of the team to join them on the roof and complete the BeamHit exercise. Then each man will rappel down to the street.[PAGEBREAK]

5:10 p.m.: Scenario Village

The Alameda County Sheriff's Department training center in Dublin, Calif., includes a series of wood frame homes called Scenario Village where academy recruits and veteran officers alike can train to answer high-risk calls.

This afternoon Scenario Village is the setting for Urban Shield Scenario #23, a combined SWAT and K-9 operation. In the scenario, terrorists have just attempted to steal weapons-grade plutonium from the nearby Lawrence Livermore Nuclear Laboratory . They were foiled by the lab's security and a gunfight ensued. The terrorists escaped, taking a lab worker hostage. They have just been stopped here in Scenario Village by patrol officers.

The Newark, Calif., SWAT team listens carefully to the scenario briefing. They are told the situation and told that they have the assistance of a patrol K-9. They also are given the option of using a First Choice MUST ballistic shield .

They move up to Scenario Village and exchange fire with the terrorists. A terrified hostage-played very effectively by Dep. Noelma Angulo of the Alameda SD-crawls to safety wailing, "Help me! Please help me!"

A K-9 is sent after one of the terrorists, and he gets his bite. The other terrorist runs into one of the wood frame houses. Newark SWAT forms a stack, and the K-9 is sent in for another bite with the team on his tail. The scenario ends very quickly.

"You showed great restraint," the tactical evaluator tells the team later in his debriefing. Hostage Angulo agrees. This team didn't shoot her, but over the course of the day she's caught rounds in the face, arm, and stomach. "It happens," she says.

"This was hard," Sgt. Jeff Mapes tells me as he walks to the team van. "We were dealing with two threats at once."

DAY TWO

10:30 p.m.: The Shoothouse

"Sniper one, you are cleared to go hot. Load and make ready," orders the scenario director.

The sniper from the Sacramento Police SWAT team is on top of a truck adjacent to a live fire shoothouse on the Alameda County Sheriff's range. His attention is downrange anticipating a target.

And he gets one. A Northern Lights Tactical Robot zips out into the kill zone sporting a metal target. The sniper fires. Scenario #22 has begun.

As I watch from atop a catwalk overlooking the shoothouse, Sacramento SWAT effects a hostage rescue.

Flash-bangs detonate, numerous shots of 5.56mm frangible ammo are fired at stationary and robotic targets, then silence.

The shoothouse cleared, the team quickly realizes that the scenario planners have thrown them a curve ball. The team assaults an outbuilding, and the hostages are rescued.

Sacramento PD Sgt. Al Miller and his team look tired to me. And they should be; they have been running and gunning for some 28 hours. But Miller tells me they are doing fine. "When the exercise gets going, you don't really feel the fatigue," he says.

11:20 a.m.: Oakland Amtrak Station

The Mountain View Police Department SWAT team has loaded up on the front and rear of a Rook tracked armored vehicle, and they are making an assault on a passenger car where armed disgruntled workers have taken passengers hostage.

The Rook moves into position, and the team deploys from the vehicle's armored platforms. They enter the train, neutralize the hostage takers, and rescue the hostages.

I'm invited onto the train after the scenario. This wasn't an easy battle for any of the teams. A train car is one long fatal funnel. In a real tactical operation, it would be bloody, very bloody.

Lt. Chris Hsiung of Mountain View PD is at the exercise observing the team, and he agrees with my assessment that a train assault would be hairy. But he says training in such difficult operating environments is what Urban Shield is all about.

"There's something to be learned in each scenario," Hsiung says. "For example, in this scenario, the team has to work in very close quarters down the aisle of a passenger train. They also have to decide the best way to enter the train."[PAGEBREAK]

12:30 p.m.: San Lorenzo High School

Welcome to my nightmare.

I am standing on the floor of the girl's gym at San Lorenzo High School in the city of the same name. The lights are dimmed, the gym is full of simulated smoke, and four terrorists are holding 15 students at gunpoint. "Bombs" are rigged into the basketball hoops.

This is Scenario #19. And it's really creepy, especially for anyone who has studied the 2004 school massacre in Beslan, Russia.

Outside, the SWAT team from the San Francisco FBI office is working with a member of the Alameda County SD's bomb squad to make a dynamic entry. The team members know they have to enter fast and knock the terrorists off balance. So they are going to explosively breach into the school.

There's a loud crack.

And the FBI is in the building. Gunshots and screams. Hostages are ordered to get down. Then quicker than I could have imagined, the team has eliminated the "terrorists," including one hiding in the locker room adjacent to the gym floor.

The team now issues orders to the hostages. Each hostage is instructed to stand up, hands on his or her head. "Move quickly! Move quickly!" one of the FBI agents barks, as each hostage is escorted to safety and checked to make sure that he or she isn't a wolf in student clothing.

The FBI team and the hostages exit out the door they came in. I walk out with the "terrorists."

The shooter in the girl's locker room was Tim Bales, a school resource officer who works at San Lorenzo High. Bales praises the performance of the FBI team. "They were really good and really fast," he says. "They picked me up very quickly, identified me as a threat, and lit me up."

3:15 p.m.: Alameda County SWAT Van

Team leader Sgt. Ken Gemmell has graciously surrendered the front passenger seat to me. His only request is that I don't step on the team's supply of Pop-Tarts.

The team's large panel van is crammed with equipment and men. Its front passenger side floor is covered with boxes of snack foods and MREs.

"We're sponsored by Pop-Tarts," jokes one team member.

Earlier this afternoon, the team finished the 13-mile run, setting the course record, averaging about 4.5 miles per hour. And they've been up and working for basically 33 straight hours. They should be exhausted, but they are in very good spirits.

"We all feel good," says Gemmell. He and some of the men admit that they have caught a few catnaps while waiting for scenarios to begin. "Sometimes you get 15 to 30 minutes," Gemmell explains.

More than sleep, their biggest concern has been food. "I tried one of the new MREs," one officer says. "I didn't finish it."

I ask about injuries. "We've had some blisters," Gemmell says. Two of his teammates pipe up with other answers. "Hurt feelings," says one. "Broken hearts," adds the other.

We arrive at Exercise #6 in downtown Berkeley, a hostage rescue inside a vacant public health building just off the University of California campus that has been dubbed "Schwarzenegger Hall."

4:30 p.m.: Schwarzenegger Hall

I am escorted to a classroom on the first floor to join other "hostages." There we receive instructions from Rob Westerhoff of the Berkeley Police Department. He tells us not to stand up once the shooting starts. Sound advice.

On the fourth floor of the building, the scenario has begun. Sgt. Gemmell and the men of Alameda County SWAT are confronting a group of animal rights terrorists. At some point, one of the terrorists will disengage and run down here to hold us hostage. It could take a while. There are multiple active shooters in the scenario.

Westerhoff tells us that this team is moving really fast. "They're coming," a role player says ducking into the classroom. That's a cue for us to put in our ear plugs, don our Simunition masks, and sit still.

Behind me one of the role players snaps off a few deafening blanks from a revolver. Then the team enters and takes out the shooter.

The scenario is over and Westerhoff gathers the hostages in the lobby. He thanks them for their service today. Acknowledging that these civilians have given up their Sunday, he tells them, "Your help with this training could mean the difference between life and death for somebody in a real school shooting."

5:15 p.m.: Losing Is Not an Option

Out in the parking lot of Schwarzenegger Hall, the men of Alameda County SWAT wait to move on to their next scenario as the Los Angeles County Special Enforcement Bureau team arrives. In the spirit of good-natured competition, officers from the two teams chat about the exercises and their performance.

No one knows it at this point, but LASD SEB will be the eventual winners of Urban Shield. Regardless, this has been a unrelentingly brutal day for team leader Sgt. Thomas Giandomenico.

Earlier this afternoon, Giandomenico smacked his head into the landing gear strut of the FedEx plane in the airport scenario. His wound required nine staples to close it. Medical personnel asked him to leave the competition.

But he soldiered on, even though the next event that his team faced was the 13-mile trail run. On that run Giandomenico and his teammates chose to wear their boots instead of trail shoes. Giandomenico lost three toenails on the run.

The next night at the "Final Exercise, the awards banquet," Giandomenico explains how he split his head open during the aircraft scenario. "I was disabling the landing gear. I've done that operation many times. Except when I do it back home, I wear my helmet. So I don't worry about bumping my head. This time I didn't have my helmet on because I can't wear it and the Simunition mask."

I follow up with the obvious question: Why didn't you drop out when the medical staff suggested that you call it a day?

Giandomenico looks me square in the eyes and says with reservation, "Losing wasn't an option."

Giandomenico's words could serve as the motto for every team that endured the grueling 48 hours of Urban Shield 2008. They all learned new tactics, new skills, and gained more confidence in their ability to handle the most difficult critical incidents. Winning was their only option, and none of them are losers.

QUESTION ANSWERED

Leaving the closing banquet, I flip back to page one of my notes. And there is my question from breakfast on orientation day: What makes Urban Shield so great?

I now have the answer.

Over the weekend, I have seen dozens of SWAT officers run through complicated scenarios and gain hands-on time with new police technologies and products such as the TASER Shockwave Area Denial System and Recon Robotics robots. They have worked in low-light conditions and in bright sunlight. They have fired thousands of rounds of marking cartridges in force-on-force combat with other experienced officers. They have fought battles in train cars, on sweltering aircraft, in cramped industrial sites, in crowded school buildings, and on moving boats. They have improved their teamwork, bolstered their confidence, and learned to stay in the fight-regardless of fatigue, pain, or injury-until the hostages are rescued and the "tangos" are down.

Is Urban Shield the best tactical training exercise in America? Absolutely.

A special thanks to Sheriff Greg Ahern, Lt. Gary Berge, Sgt. J.D. Nelson, Sgt. Ray Kelly, and the men and women of the Alameda County Sheriff's Department for their hospitality during Urban Shield 2008 ( www.urbanshield.org ).

To view the photo gallery from the 2007 event, click here .