NEW YORK CITY (TIP): A fiery explosion Thursday, March 26  afternoon in Manhattan’s East Village injured at least 19 people, damaged four buildings and led to the collapse of at least one of them.

Neighborhood residents said the initial blast shook buildings blocks away and shattered windows. Much of an exploded storefront spilled onto Second Avenue at East Seventh Street.

Four people were in critical condition; they were among 15 taken to area hospitals, including four firefighters, who sustained minor injuries. Four people were treated at the scene.

As of Thursday night, officials said they knew of no one killed by the explosion.

“We are praying that no other individuals are found injured and there are no fatalities,” Mayor Bill de Blasio said during a news conference.

The fire appeared to be gas-related, he said, though many details about the blast were still being investigated.

The explosion, which sent flames into the sky in the East Village, occurred shortly after 3 p.m., according to police. Officials were still fighting the blazes hours later, and smoke could be detected in Midtown, several miles away.

Officials warned people about air quality in the area around the blast. The explosion snarled traffic across much of downtown.

Four buildings were affected by the collapse, officials said, possibly displacing hundreds of residents. In addition to the collapsed building, two other buildings had partially caved in, fire officials said.

The American Red Cross set up an emergency center several blocks away for residents who couldn’t go home, like Karen Bienert, who heard a “really loud boom.” Some of the paintings in her apartment fell off the wall.