8 Dead in Manhattan Building Collapse

Updated: March 13, 2014, 7:17 p.m. E.T.

At least eight people were killed and dozens injured on Wednesday in a “major explosion” in New York City that razed two buildings to the ground and caused a five-alarm fire, officials said.

New York City Mayor Bill de Blasio said a gas leak was to blame for the explosion and subsequent collapse of two buildings in the East Harlem neighborhood of Manhattan and warned that the accident had a “very heavy impact on the surrounding buildings.”

“This is a tragedy of the worst kind, because there was no indication in time to save people,” de Blasio said.

The death toll climbed to eight Thursday evening as rescue workers pulled another lifeless body from the mountain of debris at 1644 Park Avenue. At least 60 were reported injured and another five were still missing as of Thursday morning. Rescue efforts have been hampered by smoldering pockets of fire and a sinkhole caused by a water main break beneath the rubble.

Mayor de Blasio said rescue teams would be searching through the rubble of the building for survivors. “Those who are missing could well be safe in another location,” de Blasio said. “There’s a tremendous amount of anxiety, but suffice it to say that every effort is being expended to locate each and every one of these individuals.”

A resident in one of the destroyed buildings said tenants had complained to the landlord about the “unbearable” smell of gas fumes as recently as Tuesday and that fire officials were called to the building weeks ago when the odor was particularly pungent, the Associated Press reports.

Two-hundred-and-fifty firefighters were at the scene battling the five-alarm fire that broke out in the wake of the explosion, officials said. The collapse filled the area with smoke, and snarled public transit and traffic in the area.

“You hear loud noises in our area fairly frequently,” says Rex Isenberg, a 26-year-old music student who lives seven blocks from the scene. “But this was above the norm.”

“There was smoke everywhere,” he says. “I actually thought it was a bomb.”

Write to Charlotte Alter at charlotte.alter@time.com.