By Mike Puccinelli

(CBS) — A shooting at a CTA Red Line station late Wednesday night ended with two people in critical condition.

Police are now trying to piece together exactly what led up to the gunfire.

CBS 2’s Mike Puccinelli reports it was just before 11 p.m. when the shooting took place in the mezzanine area of the station.

Police say it started after a man and a woman got into a fight. Then investigators say the man pulled out a gun and started firing.

The woman, 41, was shot in the knee and stomach and the man 25, was hit in the chest. They were both taken to the hospital in critical condition. Another man was, 24, also hurt by flying glass and was in stable condition.

Police say the shooting victims are improving.

“They say he’s doing pretty good and he’s talking,” said the grandmother of one of the victims.

CBS 2’s Jeremy Ross reports as the family hopes for a swift recovery they are reminded this isn’t the first time they’ve dealt with a shooting.

“I got shot up and carjacked in 1984 so I got bullets here and my stomach and all,” she said.

The shooter is still at large.