4-alarm fire erupts at apartment building in Bethlehem, Pa.

BETHLEHEM, Pa. (WPVI) -- Firefighters battled a four-alarm blaze at an apartment building and condo complex in Bethlehem, Pa. on Friday.

It happened at Five 10 Flats in the 500 block of 3rd Street.

The fire was reported around 1 p.m. At one point, a large column of black smoke could be seen over the city.

Chopper 6 was over the scene to find heavy damage to the roof, and firefighters working to put out the flames.

So far, there is no word on any injuries.

The cause of the fire is not yet known.

Stay with Action News and 6abc.action.news as this story develops.