A Penelec employee works along Eighth Avenue to investigate the cause of a power outage that affected about 234 customers Wednesday afternoon. Mirror photo by Matt Churella

Although details remain under investigation, a reported underground explosion left about 234 customers near the Altoona Area Junior High School without power Wednesday afternoon, forcing the district to send staff home early and cancel its afternoon activities, including a senior academic awards banquet at the high school.

A Penelec employee the Mirror spoke with said an underground primary — a buried high-voltage electrical distribution line that carries power from a utility grid to a local transformer — reportedly caused a manhole to be blown off somewhere on Eighth Avenue near the district’s campus.

“Something failed in there and blew the manhole off,” the employee said. The employee was working to isolate the power outage and get as many customers back up as possible as a crew made their way to investigate the details.

According to Paula Foreman, the district’s community relations director, the outage occurred about 3:30 p.m.

By that point, most of the high school’s students and staff were already gone for the day, but Penn-Lincoln Elementary has a later dismissal time, Foreman said.

“We dismissed everybody (at the high school, junior high and Penn-Lincoln) because we lost everything as far as power is concerned,” Foreman said. “We’ve canceled all of our after school activities and evening activities that might occur at the affected buildings.”

Foreman said the senior academic awards banquet will be rescheduled, but the district doesn’t have a date planned yet.

The Altoona Police Department was called to direct traffic in the area, where some traffic signal lights reportedly lost power, until officials were able to get generators in place. An officer the Mirror spoke with at the station said they did not know the cause of the outage because Penelec was still investigating.

Mirror Staff Writer Matt Churella is at 814-946-7520.