By Vi Nguyen

CHICAGO (CBS)– A fire broke out at a five-story apartment building in Logan Square around 2 a.m. Saturday.

Firefighters were called to an apartment building near Fullerton and Sawyer.

Crews evacuated the building after seeing smoke coming from one of the units on the second floor. The fire spread and damaged a nearby building.

A man and a woman were taken to the hospital in critical condition.

A woman, who lives on the second floor described how neighbors helped each other during the fire.

“Our whole apartment was filling with smoke but none of the detectors were going off, so everyone started getting out and knocking on everyone’s doors to get out of the building,” tenant Mary Abel said.

The cause of the fire is not known at this time.

This is a developing story.