Woman injured in manhole explosion in Montgomery County

ARDMORE, Pa. (WPVI) -- Police are investigating an explosion inside a manhole that injured a Montgomery County woman early Thursday morning.

It happened shortly after 6 near Ardmore and Lancaster avenues in Ardmore.

Police say the explosion happened underground.

The force of the blast blew the lid off of the manhole, which then hit the 50-year-old woman in the ankle.

The explosion also knocked out power for several hours to some residences and businesses in the surrounding area.

Crews restored service around 3:30 p.m.

It's not yet clear what caused the explosion.