In Colorado, a high school student remains in a coma, as investigators retrace the steps of another student who intended far more damage.
Colorado's governor says lessons learned from earlier school shootings saved many lives.
Friends are praying for the recovery of 17-year-old Claire Davis. She is in critical condition after being shot point blank at her Colorado high school on Friday.
"She is an innocent victim," said Arapahoe County Sheriff Grayson Robinson. "I believe that she was in the wrong place at the wrong time."
Davis happened to be in the hallway when investigators say 18-year-old Karl Pierson walked into the school with a shotgun, an ammo belt strapped to his chest. He also had a machete and three Molotov cocktails."It is our strong belief that he came to this school with that weapon and with multiple rounds, and his intention was to utilize those multiple rounds to cause harm to a large number of individuals," Robinson said.
But he never got that chance.
The entire incident lasted less than a minute and a half. Pierson fired five shots and lit one of the Molotov cocktails in the school library. Investigators say a sheriff's deputy assigned to the school rushed to the library, where Pierson fired one final shot to kill himself.
"The shooter was very, very well aware that the deputy sheriff was in his immediate area," Robinson said.
Students began evacuating immediately after the first shots were fired – a demonstration of lessons learned following the 1999 shooting at Columbine High School, just eight miles away from Araphoe High.
Colorado Gov. John
Hickenlooper, appearing on CBS News' "Face the Nation," said Sunday morning that lessons from Columbine and other shootings saved lives.
"Having had these episodes in the past, we do have strategies and protocols in place where we had a deputy sheriff in the building who immediately ran towards the trouble," Hickenlooper said.
"The school also issued an immediate lockdown of the facility," the sheriff said. "The quick response of our resources officers caused the children of this school to be safe."
The chaos of Friday has given way to quiet tributes. Students will be allowed back on Monday just to retrieve their belongings. Arapahoe High will be closed at least through next week.