The accident happened at Washington and Kostner.
Another woman and her two children were also hit but survived.
Firefighters and paramedics worked to keep mother alive as they possibly could. Doctors delivered her baby by way of emergency C-section. The baby boy is in extremely critical condition and doctors say it may be 24 hours before they know what his survival chances are.
There was no opportunity to move. Kim Brown, her friend Jennifer Cole, and Cole's two young children were hit when two vans collided at Kostner and Washington. One vehicle had apparently ran a red light and the force of the collision tossed the other directly at the women and children.
When firefighters and paramedics arrived they saw immediately that 27-year-old Kim Brown's injuries were "devastating" and also that she was well into a pregnancy.
"Once we then triaged the rest of our patients, we decided that she was going to be the priority and we were going to save her to save her child," said Tony Behland, Engine Company 95.
Brown had only a faint pulse and very labored breathing.
"I put a tube down into her lungs and…I secured her air way and we started doing CPR on her," said Captain Jill Gariti, Ambulance 15.
Paramedics continued that CPR all the way to the hospital. They managed to keep her alive until they got to the hospital. Brown's injuries, though, were too severe and she died shortly after arriving at the hospital. Doctors delivered her son by C-section.
"Obviously there are challenges when a baby is premature. But these challenges are exacerbated by the fact that there were a number of injuries the baby sustained in the accident," said Marcel Bright, Stroger Hospital spokesperson.
Doctors say the baby is in extremely critical condition. Brown's good friend, Jennifer Cole, remained hospitalized on Wednesday night but she is expected to be OK.
For the firefighters and paramedics, including one in his first day on the job, there is, at least, the knowledge they did the very best they could.
"We're happy for the outcome of the baby…very sad, very distraught about the mother but we were very happy we could help that baby," said Gariti.
The driver of the van that caused the accident faces several traffic citations, including running a red light and driving on a suspended license.