LOWELL — Thick plumes of smoke curled out of the windows of the multi-family home on Parker Street around dawn, then bursts of bright orange flashed.

A woman standing on the sidewalk cried for help, screaming that someone was still inside as a fast-moving blaze engulfed the home shortly before 6:30 a.m., neighbors said.

Fifteen minutes later, firefighters emerged from the back of the house carrying a small boy covered in dark soot.

Sophiane Em, 20, said she called 911 after her mother noticed smoke pouring from the windows of their neighbors’ home, then ran outside.

The woman on the sidewalk, whom she did not know, was crying, “My son, my son,’’ Em said.

Firefighters laid the child in the street, said Alyson Lumenello, 36, another neighbor, and firefighters quickly began CPR.

“ ‘We got the baby!’ ’’ Lumenello, 36, said she heard one firefighter shout.

Em said the firefighters spoke to the boy, trying to revive him.

“They were talking to the kid saying, ‘Please, please, please.’ ’’ Em said. “I couldn’t watch the whole thing.’’

In the end, they could not save the 3-year-old boy, and he was pronounced dead at Lowell General Hospital.

A man and an 8-year-old child, who suffered from burns and smoke inhalation, were taken to Lowell General Hospital with non-life-threatening injuries, said Lowell Fire Chief Jeff Winward.

The 3-year-old was not identified by officials, but his grandfather, Doug Knox, identified him in a brief telephone interview Friday night as Hunter and said the family had set up a GoFundMe site to help.

“It’s just been a horrible day for everybody,’’ Knox said, describing the child as “a sweet, funny, lovable, innocent little boy.’’

He said he expected the man and the child hurt in the fire to survive.

Winward said the boy was pulled from a bedroom on the second floor at the back of 57 Parker St.

When firefighters arrived on scene they were told that a child was missing.

“We tried searching the building as much as we could and we had to back out until we had a continuous water supply,’’ he said. “Then we got back in and found the child in the back bedroom.’’

Winward said it took 15 minutes for firefighters to get to the boy.

“There was too much fire and heat and fire coming up the stairs ... we couldn’t make it past the entryway.’’

The firefighters were pushed back by heavy flames as they were trying to search for the boy, said Winward, and it took them 90 minutes to extinguish the fire. Two nearby hydrants were frozen, and at one point firefighters ran out of water, he said.

Winward said firefighters found one smoke detector in the basement but they did not know if it had been working.

Middlesex District Attorney Marian T. Ryan, whose office is handling the joint investigation with the state fire marshal’s office and Lowell firefighters and police, said officials believe the injured man and the 8-year-old are related to Hunter. A firefighter who responded to the scene was also taken to the hospital for treatment of smoke inhalation.

Nine other residents who lived in the three-family building were accounted for, said Winward. He said the blaze consumed all floors of the building.

The boy’s death left first responders heartbroken.

“It’s very difficult for many of our firefighters, especially for people who have children of their own,’’ said Winward, who has children and grandchildren. “The last thing these guys want to see is a child not make it. It was very sad, very chaotic.’’

He said counselors would be available to firefighters.

The boy was the fourth person to die in a fire in the state this week.

On Wednesday shortly after midnight, an elderly couple was killed in a blaze in Malden, and four hours later, a Honduran immigrant died after a boiler he was trying to fix inside his Revere building exploded.

Twelve people in the state have died in fires so far this year.

The cause and origin of the Lowell fire is still under investigation, said Jennifer Mieth, spokeswoman for the state fire marshal.

Winward said officials will check to determine whether there were any code violations at the home.

One woman walking from the house with her niece who had lived there said, “It’s a really tough day . . . the fire, her and the kids . . . ’’

The women did not identify themselves and declined to comment further.

Em said that although she did not know the family, she sometimes saw them in the yard during the warmer months.

“I’d see them play outside,’’ she said.

A Thomas the Train toy truck sat in the snow in the front yard Friday afternoon. Two bikes belonging to a 16-year-old who lived at the house were chained to a tree in the yard. The teenager’s friends stopped by to get them for him.

“We’re always there for him,’’ said Anthony Mak, 16. “I feel really bad. I’m glad he and his family made it out.’’

Mak said his friend lived with his brother and mother on the second floor of the house.

During a press conference Friday morning, the Lowell city manager, Kevin Murphy, praised first responders for their efforts.

“Lowell firefighters . . . did a heroic job in battling this fire, and saving as many lives as they could during this tragic event,’’ he said.

Andy Rosen and Steve Annear of the Globe staff contributed to this report.