Almost a year to the day after the massacre of 26 in Sandy Hook school in in Connecticut, a student has opened fire in a Colorado school, wounding two students before killing himself.
The shooter entered Arapahoe High School, Centennial, with a shotgun at 12.33pm on Friday and asked other students the whereabouts of a staff member he wanted to confront, Sheriff Grayson Robinson said.
When the teacher realised he was the target he fled, and it is understood he may have been fired on. Sheriff Robinson praised him for seeking to defuse the situation.
One student was shot when confronting the shooter and was taken to hospital suffering serious injuries.
A school janitor told the local 7NEWS that he saw a student dressed in tactical gear running through the school.
"It just looked weird," he said. "He went in and I heard two pops. That's when I knew. I said, 'They are shooting in the school.' "
The janitor called for help and took the threatened teacher to his truck.
Police arriving at the scene immediately followed “active shooter protocol” entering the school and looking for the gunman. Within 20 minutes they found the suspect dead.
"I want to again repeat to you the suspect has been found inside the school ... deceased as a result of what appears to be a self-inflicted gunshot wound," Robinson said.
During their search they found a second student who had also been shot but only suffered minor injuries.
Student Courtney Leytoldt, told 7NEWS she was in yoga class when she saw another girl covered in blood running down the stairs yelling, "Help me, help me, there's a shooter." The yoga teacher hid students in a closet.
Another student told another local media outlet, KDVR, "Our teacher was trying to calm us down, a couple people were crying. We turned off the lights and locked the doors."
Colton Powers heard gunshots while he was in an English class, he told KDVR. The teacher turned off the light and locked the door while the students hid in a corner, he said.
Having found the dead suspect police began taking students by bus to a nearby church to be reunited with their parents. TV cameras showed dozens of students leaving the school with their hands up and undergoing what appeared to be pat-downs before they boarded the buses.
The shooting happened 25 kilometres from the site of the massacre at Columbine High, where 13 were killed by two students in 1999, and 12 kilometres from the cinema complex in Aurora, where 12 were killed last year.