Investigators looking into a central Pennsylvania row home fire that killed four young children and a woman have zeroed in on a first-floor space heater, a dead battery in a smoke detector and nailed-shut windows, officials said Tuesday.

Dauphin County Coroner Graham Hetrick said all five died of smoke inhalation, thermal burns or a combination of the two in the Monday night blaze that destroyed their home.

He identified the victims as Cornelia Brooks, 49; Kelli Franklin, 4; Tysheen Terry, 4; Deandre Terry, 3; and Derionn Terry, 2. Brooks was Kelli's grandmother and a great-aunt to the other three, said her husband, Ralph Brooks.

Ralph Brooks said Vicky, as she was known, was cheerful person who loved the children. They were separated after 15 years of marriage but remained best friends.

"I know in my heart, when the tragedy happened, she came and got those kids and took them with her" to heaven, he said.

All the victims were pronounced dead at hospitals, and no autopsies were conducted, Hetrick said.

A family member owned the home, Ralph Brooks said. It had at least one smoke detector, but its battery had died, Harrisburg fire officials said. The fire occured about a block from the Pennsylvania Farm Show complex in a poor section of Harrisburg, the state capital of about 47,000 people.

Local teens tried to get into the home from the back to rescue the occupants before firefighters arrived, but the blaze was too intense, said Janie Porter, who lives at the end of the block of five connected row homes.

Deandre was a Spiderman fan, and Derionn loved doing flips, she said.

"They were some happy babies," Porter said, standing by a makeshift memorial across the street from the home, decorated with photos of the children and stuffed animals. "They were some happy little people."

Tysheen enjoyed cartoons, and Kelli was a typical little girl, said Lisa Long, Vicky Brooks' sister.

"Everybody loved those kids — everybody," she said.

Harrisburg Mayor Linda Thompson said she would convene a task force to examine ways to improve compliance with the city's smoke detector ordinance. She said second-floor windows had been nailed shut, but it was not known if that prevented escape.

Thompson said it was unclear how many smoke detectors were in the home, but there was at least one, and its battery was dead.

The electric space heater was considered "a direct link to the fire," she said.

Ralph Brooks said the family will probably have a group funeral.