An explosion in an underground electrical vault damaged an apartment building Thursday morning in North Hollywood.

The explosion was reported below a 32,000-square foot apartment building in the 5600 block of North Farmdale Avenue. At least one unit’s windows were damaged in the blast at the three-story building.

“The forceful blast, heard over a wide area, as well as concrete debris from the electrical vault’s lid, caused damage to the eve line of the structure and broke multiple apartment windows,” the Los Angeles Fire Department said in a statement.

No injuries were reported. 

Firefighters said it appears the explosion happened in an underground electrical vault. Aerial video appeared to show a vault cover dislodged by the blast.

A utility crew and building safety inspectors were on their way to the scene.