A student at a suburban Denver high school set himself on fire in the school's cafeteria today and is in critical condition, authorities said.
A female teacher was treated for minor cuts when she broke a pane of glass to access a fire extinguisher and a school custodian used the extinguisher to put the fire out, Westminster Police Investigator Cheri Spottke told ABC News.
The student, who is 16 but otherwise not identified, is in critical condition with severe burns, Spottke said.
The incident happened at 7:12 a.m. in the cafeteria of Standley Lake High School in Westminster, Colo. Police said students were present in the cafeteria at the time, but none were injured.
"At this time we do believe that this was a suicide attempt," Spottke said.
Investigators do not know why the boy set himself on fire, and are talking to his friends, school employees and his parents for clues, Spottke said. They are also reviewing surveillance video from inside the school cafeteria, police said.
Police would not comment on whether the boy said anything before lighting himself on fire, or if he had doused himself in gasoline or any other accelerant.
Spottke told ABC News affiliate KMGH, "We don't know of any threats ahead of time at this point but that's something that we're looking into obviously-social media and that type of stuff we're looking at to see if there were any threats made."
She added, "We're taking the most precautionary measures. Nowadays with everything that happens in these schools, we're going to go through the entire school- room by room, floor by floor, to make sure there's not any other devices or anything like that."
School is closed today and Tuesday, and counselors are being brought in to help, police said.
Today's incident was the latest to affect a Denver-area school in recent weeks.
On Thursday, Columbine High School, where two gunmen killed 13 people in 1999, went on high security alert after receiving a series of threatening phone calls. The alert applied to a half-dozen other schools in the area, in the same school district as Standley Lake, but was lifted the same day.
On Dec. 13, student gunman Karl Pierson, 17, fatally shot Claire Davis, a 17-year-old classmate at Arapahoe High School in Centennial before killing himself in the school's library. Pierson reportedly had threatened a teacher and librarian who had disciplined him last year and allegedly was seeking that teacher when he entered the school, investigators have said.
Westminster was home to 10-year-old Jessica Ridgeway, who was abducted on her way to school and killed in 2012. Austin Sigg, who was 17 at the time of the crime, was sentenced to a life sentence plus 86 years. Jessica's disappearance put Westminster and neighboring Denver suburbs on edge as police, aided by an army of volunteers, searched for her and then her killer.
The Associated Press contributed to this report