CLEVELAND, Ohio (WJW) — Investigators with the Cleveland Division of Fire are trying to figure out what caused a house fire that killed a child and sent a firefighter to the hospital.

Firefighters were called to a house on E. 68th St. near Harvard Ave. just after midnight Wednesday.

Two adults and three children living inside the home got out safely.

Chief Angelo Calvillo, Cleveland Division of Fire, said the children’s mother told them one of her four children was unaccounted for.

“Our companies immediately went to go for a search and rescue,” he said.

An 8-year-old boy was found in a second-floor bedroom. Calvillo said the child was a twin.

“We’re very aggressive to begin with,” Calvillo said. “But when we find that kids are trapped it really ramps it up for us. We all have children and loved ones. Our members are a very aggressive fire department and we’re hurting tonight for that family, that mother and those children.”

Calvillo said the home did have working smoke detectors.

“Thank God for the working smoke alarms. The mother did hear that smoke alarm and got her children out,” he said. “It’s a sad night.”

“Those working smoke alarms, even in this scenario, if it wasn’t for the smoke alarms if she didn’t wake up and it would have been more than one,” Calvillo said. “It’s a sad day even losing one.”

One firefighter suffered burns on his hand and was taken to MetroHealth Medical Center for treatment.

The Red Cross was called to the scene to assist the family.

Cleveland Fire will be searching for a cause.

Late Wednesday morning they said the fire was “unintentional.”