Propane tanks exploded and at least five buildings were damaged in a massive fire in Lawrence, Massachusetts Tuesday night. Approximately 20 people were forced out of their homes, according to the Lawrence fire chief. 

Firefighters were called to Lowell Street just after 6 p.m. after receiving multiple 911 calls. A layer of smoke covered the neighborhood. 

"Several propane tanks going off"

When crews arrived, there was heavy fire coming from two multi-family homes and propane tanks were exploding. Fire Chief Patrick Delaney said they kept the fire from spreading to several other houses.

"Our crews worked very hard, they were able to keep it out of 85 Oxford which was an occupied three-family dwelling," Chief Delaney said. "We had several propane tanks going off at one time."

Firefighters struggled in the heat to contain the fast-moving flames. Two firefighters were treated for heat exhaustion. 

"It's a hot night in the city of Lawrence," Delaney said. "Our gear traps our heat. The men and women here worked very hard to save a lot of property."

Delaney said at least two of the buildings are a total loss. They will assess the damage to the other buildings on Wednesday.

"It's scary"

In the sea of red lights and haze, some families looked for their loved ones to make sure they were safe. 

"It's scary, it's scary, it really is," said resident Lisbeth Fernandes. "I don't know what's going on like, I'm trying to get home to my kids." 

The heavy smoke was a challenge for firefighters.

"It's tough, it's deep-seated, rooted fire, so it's developing a lot of smoke," Delaney said. "In tonight's humidity, it really just keeps that smoke to the ground. So a lot of our members, if you were out front, they're taking a lot of smoke in there."

MEMA, the American Red Cross and Lawrence Senior Center helped those who needed a place to stay for the night.

There's no word yet on how or where the fire started.