Detroit — Five Detroit firefighters were injured Thursday when a vacant house on fire collapsed on the city's east side, officials said.

Emergency responders were called at about 1:30 p.m. to the house on Whittaker and Mullane near Vernor Highway.

The firefighters were heading inside the building to check for occupants when it collapsed, said Detroit Deputy Fire Commissioner Dave Fornell.

"Three were initially transported and two more were just taken to the hospital," Fornell said. "We don't know the severity or seriousness of these injuries yet, but everyone has been pulled out and accounted for."

One of the firefighters was inside heading toward the back door of the building when the roof collapsed on top of them. The firefighter was pinned down in the debris, Fornell said.

"They called for a mayday, and firefighters went in and pulled him out," Fornell said. "He suffered burns, and two additional firefighters that went to the hospital are not in serious condition but needed to be checked out."

Fornell said Thursday night that the firefighter who was pinned down in the debris suffered third-degree burns. He said another one of the firefighters appears to have a leg fracture. Both were being treated at Detroit Receiving Hospital.

The other three firefighters sent to the hospital have been released and placed off duty, Fornell said.

The fire began at the back of the building and set the home next door ablaze.

Firefighters battled the fire from outside. As water from the fire engine poured in from above, white smoke exited the hollowed-out shell that used to be a home Thursday afternoon.

Bartolo Tellez, who lives next door with his wife and two kids, said luckily, no one was home when the siding of their home melted.

Other neighbors said the collapsed home previously caught fire four years ago, and there was another fire on the street in September.

Investigators are calling the incident a suspicious fire, Fornell said.

Anyone with information about the start of the fire, or who saw something they believe to be suspicious, is encouraged to call the Arson Tip Line at (313) 628-2900.

srahal@detroitnews.com

Twitter: @SarahRahal_