Kyle Bozeman remembers being roughly shaken awake early Saturday by housemate Nathan Long.

He remembers the smoke that drove him back from the doorway of his second-floor bedroom, then following Long out the bedroom window.

What he doesn’t remember was the sound of any smoke detectors, although he did recall one that went off in the house a couple of weeks earlier.

Saturday’s fire killed five people at 20 Noyes St., all from smoke inhalation, according to the state Medical Examiner’s Office.

Portland Fire Chief Jerome LaMoria would not say whether investigators have found evidence of working smoke detectors in the duplex at 20-24 Noyes St., but pleaded with city residents to make sure they have working detectors in their own homes, change the batteries twice a year and practice a fire escape plan.

“The community is grieving the loss of five young lives in a tragedy we don’t yet understand,” LaMoria said at a news conference Monday. “Until we find specific answers as to how this tragedy occurred, this serves as a reminder to do the simple things we should do every single day to ensure the safety of yourself and the ones you love.”

The State Fire Marshal’s Office is leading the investigation and will not release a cause of the fire or an explanation for the deaths until its investigation is complete, LaMoria said.

“We want to make sure we take the meticulous steps that are necessary to find out how that happened and take the steps we can to make sure it doesn’t happen again,” he said.

The State Fire Marshal’s Office requested that the city not release inspection records for the property because they are considered part of the investigation, LaMoria said. He also wouldn’t say whether investigators believe the fire is suspicious.

LaMoria did release the identities of the people who were killed:

Maelisha Jackson, 26, of Topsham, and Chris Conlee, 25, of Portland, were both visiting the house. David Bragdon Jr., 27, Ashley Thomas, 29, and Nicole Finlay, 26, were residents. The Office of the State Medical Examiner was still working to confirm Finlay’s identity, LaMoria said. Three of the victims were found on the third floor, and two on the second.

Another visitor, Steven Summers, 29 of Rockland, was badly burned and was in critical condition Monday night at Massachusetts General Hospital in Boston.

Bozeman and Long escaped the fire, and another roommate, Justin Irish, was not home at the time.

Carol Schiller, a neighbor who was among the first to spot the fire and call 911, said “our neighborhood is devastated” by the blaze. Speaking Monday night to the City Council, Schiller recounted seeing Thomas and some of her female housemates “giggling and smiling” as they walked her dog just the other day.

“They smiled and said hello as they passed,” said Schiller, who is president of the University Neighborhood Organization. “I recall thinking to myself, ‘They are in the prime of their lives, having a blast.’ I vividly recall thinking how lucky we were on this street to have these young women as neighbors.”

Schiller also credited firefighters and police for a quick response that she believes prevented the fire from spreading.

The federal Bureau of Alcohol, Tobacco, Firearms and Explosives joined the investigation Monday, sending an expert in fire modeling that will enable investigators to re-create the conditions of the fire to try to determine its behavior. Portland police also have been helping to conduct some of the many interviews that are part of the investigation, said Police Chief Michael Sauschuck.

When firefighters arrived at 7:22 a.m., they found a fast-moving fire raging through the 94-year-old building.

Six people lived at 20 Noyes St. All the residents of 24 Noyes St., the other half of the building, escaped uninjured.

Ian Jones was a friend of several of the residents, and spent time with Thomas in particular.

“Ashley, she lit up a room everywhere she went,” he said. “I can’t imagine not being able to call her again. It’s a big hole.”

Bozeman, 23, said Friday that Finlay, Thomas and Bragdon were good friends and good people.

“They had nothing but big hearts, nothing but love,” he said.

Bozeman said he owes his life to Long.

“He told me he had to shake me for 10 seconds,” Bozeman said, recounting the experience Monday while standing in front of what remained of his home. He said he had been drinking with friends Friday night, got home at 3 a.m. and fell asleep with his clothes on.

“By the time I finally opened my eyes and figured out what was going on, (Long) was already out the window,” Bozeman said.

Long has said he woke to the sound of his alarm clock shortly after 7 a.m. Saturday.

“He said when he woke up, he smelled smoke and the ceiling was on fire,” Bozeman said. Long has said he was unable to get to other parts of the house because the smoke was so heavy.

Bozeman said he didn’t hear a smoke alarm going off Saturday morning, but had heard one activated sometime in the previous two weeks. He couldn’t say why because there hadn’t been any fires.

After Long woke him up, Bozeman said he tried to look into the hallway from his bedroom, but smoke and heat were pouring toward him. Instead, he climbed out his window onto the small roof that extends over the rear entrance.

“I yelled inside, ‘Hey, fire!’ I heard like two yells. I kept on yelling back inside and I didn’t hear any more yelling,” he said.

The heat drove him back from the house, and he jumped to the ground.

“When I came outside, the porch was on fire,” he said. A tall evergreen alongside the house ignited and burned like a torch as flames climbed the side of the house. Bozeman said he saw Summers lying in the street, badly burned.

Bozeman said he had only been sleeping in his bedroom for two days, having waited for the previous occupant to move out. Before that he slept on a couch on the first floor or in the basement, where he had stored his belongings.

He finally moved his predecessor’s belongings to the bottom of the rear stairwell, effectively blocking it as a fire escape, he said. He had suggested to his housemates before the fire that they should move the items outside, but they decided against it. He said he hoped that didn’t play a role in anyone’s death.

Bozeman said he spoke because he wanted to correct earlier reports that Long had discovered the window already opened and leapt to safety.

“I have to thank Nate for being a responsible man. If he had been out partying with everybody else, we both would be dead,” Bozeman said.

Staff Writer Kevin Miller contributed to this report.