A man and a woman were critically injured when an unoccupied building they were staying in caught fire early Tuesday in the West Garfield Park neighborhood on the West Side, according to Chicago Fire Department Media Affairs. 

The fire broke out about 3:13 a.m. at 4304 West Monroe, officials said.

The man and woman, who were believed to be squatting in the building, were injured when they jumped from the second or third floor to escape the fire, officials said. Both were taken by ambulance to Stroger Hospital in critical condition.

One of two people injured early Tuesday after jumping from a fire in an unoccupied building in West Garfield Park is taken to an ambulance | Tyler LaRiviere/Sun-Times

When they arrived on the scene, firefighters found heavy fire pouring out of the building from the third floor, according to Chicago Fire Deputy Chief Chuck Maes.

Firefighters used a deck gun and water lines on the rear and front of the building to put out the fire, Maes said.

Jonathon Anderson said he was riding his bicycle down the street when he heard a scream and heard a man shout that the building was on fire.

Anderson said bystanders gathered outside the blazing building, encouraging people to get out, and that he saw at least one person go inside the building to help a woman who could not climb down from the third floor. Shortly after, Anderson said he saw “a big ball of flame” come out of the building.

The woman eventually jumped from the third floor with a man, Anderson said.

Another man jumped from a third floor window and hung onto a ledge on the second floor before dropping to the ground below, Anderson said.

It was believed the two victims sustained injuries from falling from the building and it was unclear if they suffered burns or smoke inhalation from the fire, Maes said.

No other injuries were reported and Maes said he was not aware of any other fires in the building in the past.

The cause of the fire was under investigation. It was unclear if there were working smoke detectors in the building.