(Click HERE for WCBSTV Video) A seven-alarm fire in the abandoned Deutsche Bank skyscraper has tragically claimed the lives of two NYC firefighters. The fire sent a plume of gray smoke trailing above ground zero Saturday afternoon as firetrucks and police cars raced through lower Manhattan to reach a building already decimated by the Sept. 11 terrorist attacks.

According to 1010WINS, the firefighters were critically injured while trying to reach the fire, which began about a dozen floors up in the tower left vacant since 9/11.

One firefighter suffered cardiac arrest and another smoke inhalation. A third suffered minor injuries to an ankle, fire officials at the scene said.

The fire was burning on multiple floors at the building, where construction crews had already dismantled 14 of the building’s 40 stories — reaching the 26th floor on Tuesday. Some firefighters used stairs to reach the burning upper floors.

More than two hours after the blaze was first reported, the blaze was declared a six-alarm fire. Officials continued to push onlookers further back from the building and set up a command post on the West Side Highway. Officials could be seen poring over a map of the area.

The cause of the fire was unknown. Smoke pouring from the burning building was visible from midtown Manhattan and the New Jersey side of the Hudson River.