Firefighters on the scene of a fire that killed a North Mayfair woman. WGN-TV

Firefighters on the scene of a fire that killed a North Mayfair woman. WGN-TV (WGN-TV / January 17, 2013)

A basement fire that killed a 35-year-old woman and injured her daughter is being investigated as a possible arson, authorities said today.

Claudia Martinez, 35, suffered severe burns in the fire Wednesday night in the basement of the two-flat where she lived in the 4800 block of North Kenneth Avenue, according to the Cook County medical examiner’s office. The fire started about 10:15 p.m. Wednesday, and Martinez and a 6-year-old girl were taken to Swedish Covenant Hospital following the fire, said Chicago Police News Affairs Officer Veejay Zala.

Martinez was transferred to Loyola University Medical Center’s burn unit, where she was declared dead just before 6 a.m., according to the medical examiner’s office. Neighbors told WGN-TV that the girl injured was Martinez’s daughter.

The fire that is believed to have killed Martinez is being investigated as a possible arson, police said.

Neighbors who live upstairs from the Martinez family were in their second-floor apartment when they heard a loud noise, and the building’s smoke alarms started going off. Nora Fernando had been in bed, but had gotten up to get something to eat, when she was frightened by the noise at the back of the building.

“I heard something, like an explosion, and the fire alarms were going off,” Fernando, who was in her apartment with two sons, told WGN-TV.

At first, Fernando’s sons, who were in the front of the apartment, paid little attention to the explosion sound, thinking it was a firework, said Jason Javier, one of her sons, who was on a computer at the time. Then Fernando opened the front door, and they realized the front stairwell was filling with smoke.

“I thought that the fire was coming from the front, but was worse when we got back there,” to the rear of the building, and so they all three made their way back to the front stairwell and got out that way, Javier told WGN-TV.

Martinez lived in a lower-level apartment with her husband and daughter, neighbors told WGN-TV.

Fire officials weren’t available to comment this evening.

Tribune reporter Liam Ford contributed

chicagobreaking@tribune.com