Just before midnight, Chicago firefighters encountered heavy fire coming from the fourth floor of an apartment building.

A man and woman were transported for smoke inhalation while aother person suffered an ankle injury, CBS reported. 

A fourth floor resident said who escaped the fire said he heard something so loud, he thought it was a gunshot. 

"I'm like nah, I've never heard a gunshot that loud inside and sure enough I started smelling something. I was like, let me look outside of my window sure enough, there's smoke, fire, embers everywhere," Connor Weston said