A Halloween joke causes panic and severe injuries to a high school student.

ELLSWORTH (AP) – A student was severely burned Thursday when his Halloween costume was set on fire in view of hundreds of horrified classmates during a high school assembly, police said.

A 15-year-old boy made the comment “I wonder if this will burn” before touching a classmate’s costume with a lighter, said Police Lt. Harold Page.

“This is just a prank gone horrifically wrong,” Page said.

Many of the 500 students gathered in the gymnasium for “Spook Day” at Ellsworth High School initially thought it was a Halloween stunt when they saw a ball of flames erupt in the top of the bleachers.

Then pandemonium ensued at 9:43 a.m. as students began darting toward the exits. Students and staff doused the flames using a fire extinguisher and a coat, Page said.

The boy suffered burns on his back, legs and back of his head, Page said. He was airlifted to Brigham and Women’s Hospital in Boston, where he was being treated for third-degree burns. His condition was not immediately known.

The victim, Donald Awalt, 14, of Ellsworth, was wearing what was described as a homemade G.I. Joe sniper outfit in which he was dressed in camouflage and covered with leaves and a grass-like material, authorities said.

The 15-year-old boy who started the fire was remorseful and said he never intended for anyone to be hurt, Page said.

The boy was charged with reckless conduct, aggravated assault and arson and taken to a youth detention center in Charleston, Page said.

Many students had come to school wearing costumes for “Spook Day,” which was held this year the day before Halloween. No classes were scheduled Friday because of a teacher work day.

About 500 students – the entire high school – turned out for the assembly in the school gymnasium. The event features costumes, jack o’ lanterns and Halloween decoration contests, said Superintendent Jack Turcotte.

The fire created enough smoke to set off the fire alarm, which is how police were notified, Page said. The state fire marshal’s office joined local police in the investigation, officials said.

Afterward, there was another assembly in the school auditorium in which students were told what happened. Classes resumed but students were allowed to go home with their parents’ permission.

Turcotte said he hopes his students learned from what they witnessed in the gymnasium. “You just never realize how quickly an inappropriate activity like this can turn tragic,” he said.

AP-ES-10-30-03 1701EST