Sources say a New York City firefighter has been killed on the scene of a gas explosion that rocked the Kingsbridge neighborhood in the Bronx this morning.

Fire officials say crews were first called to the scene around 6:22 a.m. at 305 West 234th Street to investigate a report of a gas leak.

Sources say it happened at a two-story private residence that possibly had a drug lab inside.

More than 100 firefighters have responded.

Fire officials say there are several other injuries.

The NYPD says four uniformed officers suffered minor injuries.

New York City Emergency Management says drivers should expect traffic delays and road closures in the area.

Con Ed crews have also been dispatched to the scene.