By Jermont Terry

CHICAGO (CBS) — Three residents and a firefighter were hospitalized with minor injuries Monday evening when a fire broke out at a South Shore apartment building.

Shortly after 7 p.m., the Fire Department was called for a fire at the U-shaped courtyard building at 6916 S. Clyde Ave., according to Deputy Fire Commissioner Marc Ferman.

READ MORE: Worries Of A 'Twindemic' As Flu Season Coincides With The COVID-19 Pandemic

Firefighters arrived at the four-story, 150-foot-by-150-foot building to find the rear stairwell was on fire. The hallways were full of smoke and heat, and some occupants were trapped in their units and were hanging out windows, Ferman said.

As CBS 2’s Jermont Terry reported, there was so much intensity from the fire – not to mention thick smoke – that some people thought jumping would be the only option. Fortunately, firefighters were able to convince people to wait for the ladders.

Firefighters were able to get many of the residents out of the building using the front stairs, but some had to come down on ladders, Ferman said.

READ MORE: Simeon Career Academy Student Shot And Killed Just Blocks From School

One woman was shown on video as she was brought down on a ladder. The woman needed some fresh air after being inside the smoky burning building.

A still-and-box alarm was called, and additional companies responded. But the rear stairwell was destroyed by the fire, which limited points of exit.

Three civilians were hospitalized for smoke inhalation, and a firefighter was also hospitalized after taking a fall – possibly through the burned-out stairway. All the victims were taken to the University of Chicago Medical Center with minor injuries.

MORE NEWS: State Data Show One Chicago Nursing Home Has Fewer Than 1 Percent Of Staff Vaccinated Against COVID-19

The cause of the fire was under investigation Monday night, Ferman said.