CHICAGO (CBS) — Four firefighters were injured after being engulfed in flames while inside a burning two-flat on the West Side on Sunday.

Chicago Fire Chief Jose Santiago said the firefighters suffered first and second degree burns, and two of them also suffered minor injuries after they were forced to jump out a window to escape.

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The firefighters were listed in stable condition.

Five people were also treated at the scene but did not require hospitalization.

Six people, three adults and three children, were displaced in the fire.

The fire erupted around noon in a two flat in the 4900 block of West Potomac in the Austin neighborhood.

As the firefighters entered the building, they had trouble with the water in their hoses. As they opened doors to get to the fire, which started in the rear kitchen on the second floor, a wall of flame overtook them.

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“It’s like an explosion,” Santiago said. “It was a hot, fast moving fire.”

All of the firefighters had on their breathing masks and protective gear.

“That’s why they are alive right now,” Santiago said.

The four were all alert, Santiago said, and were asking about each other.

“It’s a very emotional time,” said Santiago, who described them as veterans of the department. “They are all asking about each other.”

Berita Conley lives in the building with four family members, she told reporters at the scene. She was alerted to the fire by a neighbor who knocked on her door.

Conley was able to get her two grandchildren, daughter, husband and dog out of the building.

“If the neighbor wouldn’t have knocked on the door, been banging and hollering, we would have all been dead in there,” Conley said.

The fire was struck out around 12:40 p.m.

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The cause of the fire is under investigation. The cause of the lost water pressure will also be the subject of an inquiry.