Firefighters battled a large fire that erupted Thursday at an apartment complex in Dallas, where debris from one collapsed building lay heaped on the ground while flames and black smoke billowed into the sky. Neighbors reported hearing a loud boom like an explosion.

News video showed dozens of firefighters at the scene. Some had hoses trained on piles of smoking debris while others lifted and moved lumber and other burned wreckage as if searching for people underneath.

Two firefighters with hoses towered above the blaze on long ladders, while another sprayed water from an upper floor window in a neighboring building.

It was not immediately known what caused the fire or if anyone was injured.

A nearby street was lined with firetrucks, ambulances and police vehicles with their lights flashing.

Julie Jensen said she was at home less than a block from the building when she heard a noise like an explosion that left her ears ringing.

“I was sitting on my couch watching TV — stuff flew off our walls,” Jensen said.

Jensen said she saw rising smoke and neighbors running when she looked out the window. She grabbed her family’s cat and left, finding a nearby parking lot to wait until she knew it was safe to return.

A spokesperson for Dallas Fire-Rescue did not immediately return phone and email messages seeking comment. The Dallas Police Department referred all questions to fire officials.

Sal De La Rosa was at work at a nearby auto repair shop when “all of a sudden we just heard and felt this huge boom.”

“We felt where the building kind of shook a little bit,” Del La Rosa said.

He said a co-worker went outside and saw thick, black smoke rising into the air.