Two buildings have collapsed after an explosion Wednesday, March 12 morning in New York’s East Harlem, CBS New York reported.

It happened around 9 am on Park Avenue on 116th Street, the FDNY said. One of the buildings that collapsed had a piano repair shop with apartments above. The second building housed a church.

It’s unclear if anyone was inside the buildings at the time of the explosion. Officials believe the buildings were both 5 stories tall.

Video from the scene shows heavy smoke rising from the area as hundreds of firefighters battle the blaze, which has been upgraded to five-alarms. Debris and rubble could be seen scattered all over the area.

WCBS 880 said thick, black smoke was enveloping the area. Police on the scene could be seen wearing face masks, CBS 2 reports.

A man who was on the 15th floor of a building on 125th Street said he saw dark smoke billowing down several blocks.

“The building shook and then we looked to see what was happening. We saw a whole lot of smoke. A lot of smoke came out,” witness Samuel Paul told CBS 2. “There’s a lot of dark smoke still coming out. A lot of fire engines I saw going to 125th Street.”

“The smoke started to rise. It looked like something fell because it wasn’t like a fire. It just looked like debris smoke, similar to 9/11,” Paul added.

Metro-North said the explosion happened adjacent to the tracks. Service in and out of Grand Central Terminal is suspended until further notice.

The bomb squad is also responding as a precaution. So far, there are reports of 11 injuries. Harlem Hospital says it has received one patient with serious trauma.

Many reported hearing a loud explosion and began posting pictures of the scene on Twitter.