To ignore the growth of criminal gangs in your city-even if you don't live in Los Angeles, Chicago or New York-could be more dangerous than you think.

Gangs are predatory by nature, and they don't play by our rules. Even small gangs are criminal opportunists, and they will exploit every situation to their advantage. This includes civil disorder and natural disasters.

Los Angles street gangs have caused or exploited major civil unrest: the Zoot Suit Riots of 1943, the Watts Riots of 1965, The Vietnam Moratorium Riots of 1971, and the Rodney King Riots of 1992.

The Big Easy is the nickname given to the city of New Orleans long ago. It got that name because it has always had an easy going tolerance of shady dealings and slightly crooked people. What we now know is that "La Cosa Nostra" ("The Mafia") had its American beginnings in New Orleans. On October 15, 1890, New Orleans Police Superintendent David Hennessey was murdered by Sicilian Mafia members. This was the first major criminal act of the Mafia in America.

In the summer of 2005, New Orleans was statistically well on its way to being one of the deadliest cities in the U.S. More than 202 people had already been murdered and another 107 or so murders were expected before 2006. Not counting tourists, New Orleans boasted a population of 450,000 making the rate of murder one for every 1,452 residents. It was more like Iraq than even Chicago or Los Angeles.

New Orleans is sometimes known as "504" (its telephone area code) in the world of gangs. Its gangs were not the big Crips and Blood gangs from Los Angeles, nor the Latin Kings or the Gangster Disciples of New York or Chicago. New Orleans gangs tended to be small local groups divided among its 17 voting districts or "wards." The Third and Galvez (3'n'G) gang or their rivals the Dooney Boys fiercely defended small turfs usually associated with the public housing projects. Often the gang would simply scrawl gang graffiti to claim "9th ward" or "KC Mob" for the Kenner City suburb.

Unlike L.A.'s crack dealing Crips and Bloods, the New Orleans gangster's primary product was heroin. These small New Orleans gangs fought violently for their small piece of the drug territory. Life was gangster good.

Nothing seemed to stem the growing gang body count. Victims and witnesses were reluctant to appear in court, or they had a change of heart before trial. They feared further gang reprisals, and the justice system was broken. A 2003-2004 study by the New Orleans Metropolitan Crime Commission showed only seven percent of suspects charged with crimes were ever sent to prison. New Orleans residents had lost whatever faith they had in the system long ago.

At approximately 10 a.m. on Sunday August 28, 2005, New Orleans Mayor Ray Nagin ordered the mandatory evacuation of the city after the National Hurricane Center declared the approaching Hurricane Katrina a category 5 storm, the most powerful rating for a hurricane.

Monday morning Aug. 29, 2005, at 6 a.m. Katrina made initial landfall with category 4 hurricane winds of 145 mph. At 8 a.m. the Army Corps of Engineers reported the following: "A barge broke loose and crashed through the floodwall, opening a breach that accelerated flooding into the lower Ninth Ward and Saint Bernard Parish." At 9 a.m. the vengeful eye of Katrina passed over New Orleans and six to eight feet of water covered the lower Ninth Ward.

By mid-morning two holes were ripped in the Superdome roof and 10,000 storm refugees, who could not or would not evacuate, were inside. Later that morning the 17th Street Canal Levee was breached. The American Red Cross announced that it was "launching the largest mobilization of resources in its history" to assist the Hurricane Katrina Victims.

[PAGEBREAK]The evacuation of the city included the populations housed in its institutions, hospitals, rest homes, psychiatric facilities, and jails. Some were transported to facilities in Shreveport and Baton Rouge, but some wound up in the Superdome and the Convention Center.

Flooding, fires, and the absence of law and order soon led to looting and murder. There were many reports of roving gangs and looters taking advantage of the chaos, even in the Superdome. Outside, bodies and sewage floated in the streets.

On Wednesday, Aug. 31, Gov. Kathleen Blanco of Louisiana ordered emergency occupation of hotel and motel rooms and the commandeering of buses for evacuation efforts. Later she ordered that all of New Orleans, including the Superdome, be evacuated. Buses began transporting refugees 350 miles away to the Astrodome and Reliant Arena in Houston.

The 1,500 personnel of the New Orleans Police Department were ordered to abandon any search and rescue efforts and to restore order to the city. Mayor Nagin called for federal assistance to control widespread looting. He ordered a citywide curfew.

On Thursday Aug. 31, CBS News reported that military helicopters and ambulance vehicles suspended their attempts to evacuate the Superdome when they were fired upon. One pilot reported: "100 people were on the landing pad, and some of them had guns."

The Louisiana National Guard under Lt. Colonel Pete Schneider, which was tasked with the evacuation of the able-bodied from the Superdome, was forced to suspend operations because of the buildings ablaze and fires set outside on the streets preventing the buses from getting close enough to pick up people. Eventually 30,000 troops would be deployed along the Gulf Coast.

World Net Daily on Sept. 17, reported that during the unrest armed gangs from as far away as Memphis, Dallas, and Miami had participated in the civil disturbances following Katrina. Col. David Hunt, a military analyst, was quoted from his appearance on FOX News' "The O'Reilly Factor" program on Sept. 16, saying "It was as bad as the early days in Baghdad." The gangs fought for turf in the deserted, flooded streets of the city for six days, terrorizing those left behind and looting shops, jewelry stores, museums, and banks.

The authorities' reaction to this was widespread and disarming: the confiscation of lawfully owned firearms from Katrina survivors by the military and law enforcement. There is a video circulating on the Internet of local police forcibly taking a gun, her only protection, from a little old lady survivor of Katrina.

If you live in one of the cities that accepted Katrina refugees, you know what followed. While most Katrina survivors were appreciative of their host communities and generally law abiding, the criminal element, mostly gangs, soon returned to their thug lifestyles. New Orleans gangs became involved in violent crime and murders, either as the suspects, victims, or both, in host cities like Houston, Sacramento, Oklahoma City, Atlanta and North Las Vegas.

In Houston, refugees began arriving on Sept. 1, and after 13,000 people filled the Astrodome, evacuees were funneled to other locations.

Eventually Houston would add an additional 150,000 Katrina refugees to its population of 4 million. Attracted to the same low income government housing that they left in New Orleans, many settled into apartment complexes in Houston's high crime southwest side.

After a few months of adjusting to their new environment and after the payment of initial refugee benefits, the New Orleans gangs began to establish themselves in the local drug and prostitution businesses. The first murder involving Katrina refugees occurred on Nov. 29, when a 21-year-old man was shot in the head at a pool hall.

Houston P.D. responded by forming a 10-man gang murder squad on Jan. 15, 2006. By Jan. 27, they had arrested eight Katrina evacuees and had charges against three more. Five more were wanted by Feb. 16.

In Houston, the murder rate between the Katrina refugees' arrival in September and March 2006 jumped up nearly 32 percent from the same period the year before. They were involved in 35 of Houston's 212 murders as victims or suspects.

Houston's schools were also affected, as 5,566 Katrina evacuated students were enrolled. Several altercations have resulted from conflicts between these students and local kids. In a December 2005 brawl at the Southwest Houston High School, 27 people were arrested. This rivalry is a foreshadowing of future conflicts and the possible basis for the formation of future gangs and gang rivalries.

And Houston is not alone. In a Dec. 21, 2007, report, the Las Vegas Sun detailed a possible mass federal eviction of Katrina refugees who had settled in the Buena Vista Springs Government housing in north Las Vegas. Of the 212 families settling there, 144 could not pass criminal history checks.

Hurricane Katrina and the flooding caused by the storm were a national disaster, and the rioting and looting following it was a national shame. But all this was magnified by the violent acts of small criminal gangs. Maybe the flooding was inevitable, but the criminal acts of those gangs were preventable.

Recently, I watched the History Channel documentary "The Crumbling of America" and I couldn't help but think about what might happen to another city. The program listed the likely failure of the Sacramento delta Levee system as the most likely national disaster threat in the near future. I hope Sacramento will not be the next New Orleans.