Four manhole covers exploded Sunday afternoon in Malden, Massachusetts, knocking out power for dozens, according to police.
Officials from National Grid believe burnt wires that are estimated to be 100 years old caused the explosion.
It happened on Main and Florence streets around 1:30 p.m. Reports of heavy smoke initially brought firefighters to the scene. When they arrived, the manhole covers started to blow.
Residents living near the area were evacuated as firefighters entered homes to check for combustible gases.
There was no visible damage to any buildings, police say, and no gas was found.
Power was out in the area, but it has since been restored.
