Explosion damages Sonic Drive-In restaurant in Port Richmond

PHILADELPHIA (WPVI) -- An explosion damaged a Sonic Drive-In restaurant in the Port Richmond section of Philadelphia early Wednesday morning.

It happened around midnight on the 2200 block of Butler Street.

Fire crews responded to an explosion in a rear electrical box.

The explosion damaged some signs by a drive-in lane.

There were no reports of injuries.

There was no immediate word on the cause of the explosion. The fire marshal is investigating the incident.

Video from the Action Cam showed the scene cordoned off by police tape and the Philadelphia Fire Department was on the scene.