Photo: The service map from Belmont Light’s webpage shows the town impacted by the outage

A manhole explosion at approximately 10 p.m. on Hittinger Street is responsible for plunging most of Belmont into the dark, according to Belmont Light, the municipal electrical utility.

The explosion and subsequent fire “caused the entire west side of town to lose power,” read a message on the utility’s Facebook account. While power remained on in the southeast section of Belmont and along Belmont Street and Trapelo Road into Cushing Square, all other neighborhoods and streets were dark. The resulting loss of electricity left most homes without power, street lights to go out, and resulted in drivers negotiating intersections without traffic signals.

Belmont Light said it has crews at the location, which is nearby to one of its transformer stations.

“We are ensuring that line workers can safely enter the manhole before determining the extent of the damage. We will provide an update ASAP,” the posting read.

UPDATE: At approximately 11:31 p.m., Belmont Light reported it had identified a failed cable and are testing others in an attempt to isolate the issue.

“We hope to start to pick customers back up within 30 minutes [at midnight, March 19] and will be making progress to restore power for all customers following testing.”

UPDATE: Belmont Light has completed the work bringing power back to the town.