FARMINGTON — A construction worker was injured Tuesday afternoon when nine of 14 roof trusses being demolished in the former gym at Mt. Blue High School suddenly collapsed, said David Leavitt, director of support services for Regional School Unit 9.

It was the second mishap of the day. School was already in the process of being called off for students Wednesday due to a power outage in the three-story classroom wing, Leavitt said.

School will be canceled at both Mt. Blue and the Foster Career and Technical Education Center as the technology staff works to restore serivce to the school’s three computer servers that are housed in the main building, Leanne Condon, spokeswoman for the administration, told the school board Tuesday night.

The district is in the midst of a $64 million construction project to expand and renovate the high school.

The worker from Hall Demolition was 20 to 25 feet in the air on a scissor lift when falling trusses apparently knocked it over and he fell, Leavitt said. The incident occurred between 2:30 and 3 p.m., he said.

The unidentified worker was conscious and alert before going by ambulance to Franklin Memorial Hospital in Farmington, he said.

Only construction workers were at the gym at the time, Leavitt said.

The unrelated power failure knocked out the lights at about 1:30 p.m. after an electrical wire was found in the wall that contractors were demolishing, Leavitt said.

A new power line will have to be pulled into the building before classes resume, he said.

dperry@sunjournal.com