Two Belmont Light workers were transported to Mass General Brigham Hospital on Tuesday morning after an accident in a manhole in the Belmont High School parking lot.
“When our units arrived on scene, we discovered there were two electrical workers that were injured,” said Fire Chief David DeStefano, who said the call came in as a medical emergency at around 9:48 a.m. “Apparently, an arc flash occurred in a manhole where they were working.”
According to a statement from Belmont Light, the two workers were able to get out of the manhole on their own.
An electric arc forms when electric current is sustained outside of its normal conductive pathway, such as in the air, according to the National Fire Protection Association. Electric arcs form due to a number of factors, such as high voltages or currents, moisture content, and damaged or degraded insulation.
DeStefano said the injured workers were treated by Belmont Rescue and Pro EMS of Cambridge before being transported to the hospital. As of early Tuesday, they were listed in stable condition, according to Belmont Light.
According to High School Principal Isaac Taylor, the accident resulted in power outages at Belmont Middle School and High School. Facilities Director David Blazon explained that power was restored using a generator, allowing classes to continue.
“I don’t know what the cause of the accident was,” DeStefano said. “That’s going to be investigated by the [Massachusetts] Department of Labor and Standards, and they’re responding to the scene.”
According to DeStefano, the Occupational Safety and Health Administration, commonly referred to as OSHA, deferred the investigation to the Department of Labor Standards because it was a municipal accident.