One firefighter was hurt while battling a fire in a vacant Sunset Park apartment building this morning.

More than 50 firefighters responded to the blaze at around 5:30 a.m. at 46th Street and 8th Avenue. Officials say the building owners were conducting an excavation and that the injured first responder fell through a 3-foot hole on the first floor.

The firefighter is being treated for minor injuries at Lutheran Hospital and is expected to be OK.

The NYPD and fire marshals are investigating.