BROCKTON ­— Five Brockton families are without homes after a two-alarm fire consumed half the first floor of their multifamily dwelling early Sunday. Firefighters rescued four people trapped on a fourth-floor balcony, but no residents were injured, the Fire Department said.

The basement fire in the 400 block of Main Street broke out about 1:45 a.m. Two minutes after receiving the call, firefighters arrived to find flames filling the first-floor apartment of the six-unit building, said Robert McGrann, a captain in the Fire Department.

Thirty-one firefighters from Brockton’s nine firetrucks were called in to help battle the blaze because several trees and an auto parts store are within feet of where the flames billowed from windows, McGrann said.

“It takes a very aggressive attack and a lot of manpower to put something like that out,” McGrann said. “You’re not only trying to put the fire out, but trying to think where is this going to be in 10 minutes.”

One firefighter was injured, McGrann said, and was taken to Brockton Hospital with an ankle injury.

The sound of sirens woke Debroah Weber, 46, who lives across the street from where the fire broke out.

“It was real bad,” Weber said. “I thought someone got stabbed or something, but this was much worse.”

“I feel bad because they lost everything,” Weber said Sunday afternoon. “I just hope they all make out OK.”

Children’s toys were scattered among the gray rubble and shattered glass. A pungent odor filled the air surrounding the building Sunday afternoon, and a man stood in the middle of it all, wiping his eyes.

The building is probably salvageable, but the two-alarm fire was “very intense” and probably caused more than $100,000 in damage, McGrann said. The cause of the fire is being investigated.

It will be some time before the residents are able to move back in. Several returned Sunday to search for belongings strewn through the burnt piles of debris.

One man climbed onto the rubble in search of old photographs his grandmother didn’t have time to grab. A mother returned for her young children’s clothes and toys. Another man rescued his lawn mower and one of his two cats. His other cat hasn’t been seen since Saturday.

Most of his belongings, however, are charred and buried under the ashes in the alley outside his first-floor window, he said. None of those at the scene would give their names.

The American Red Cross of Eastern Massachusetts is helping the victims, beginning with providing toys to help comfort the youngest victims. Among the 17 residents displaced were five children, one of them just 2 months old.

“Fires are a very traumatic experience for everyone, so we give parents stuffed animals to comfort their children,” said Kat Powers, director of communication for the American Red Cross of Eastern Massachusetts.

Along with the Mickey Mouse dolls, residents received blankets, hotel accommodations, and money for food and fresh clothes.

“Getting out of the scene where people can shower and get into new clothes is only the start of their recovery,” Powers said. “The dollar amount from today will only go up.”

The Red Cross will arrange counseling for families that request it, as well as medical consultations if necessary.