As gunshots at Saugus High School in Santa Clarita, CA, sent frightened students fleeing the building, an LASD detective, an LAPD officer, and an Inglewood police officer were dropping off their own kids. The officers ran toward the sound of gunfire, providing life-saving first aid to the victims, Los Angeles County Sheriff Alex Villanueva said.

Villanueva told reporters that lives were saved by the quick action of the off-duty officers who rushed into the school to try to confront the attacker and tend to the victims.

"Off-duty first responders were there and did not hesitate, turned around and went right into the source of the gunfire to attempt to neutralize it, and they rendered first aid immediately," he said.

They realized immediately that the shooter was down and quickly grabbed the school's trauma kits to begin treating the victims.

Other uniformed deputies from the local sheriff's station also arrived within a minute, including Deputy James Callahan, who works as a school resource officer at the high school.

In only 16 seconds, two teenagers — a 16-year-old girl and a 14-year-old boy — were killed and three were wounded Thursday at the suburban Los Angeles high school. 

The attacker, a fellow student who turned 16 on Thursday, was hospitalized in grave condition after shooting himself in the head, according to surveillance video, authorities said.