The crash caused a car carrying a mother and her two children to flip over at the intersection of Addison and Menard. They were among those hospitalized.
"I heard the ambulance first, and then all of a sudden I heard the pow," said Audrey Malkowski, witness.
Ambulance 82 was less than two blocks from Our Lady of the Resurrection Hospital. One EMT was driving, the other was tending to a patient, and that person's relative was in the back when it collided with a car carrying a mother and her two children.
"She was saying, 'God, please don't take my daughter from me, please don't take my daughter from me,' " said Edwin Martinez, witness.
Martinez saw the crash and rushed to help. He found the mother clutching one of her two kids.
"She was screaming on her hands and knees and I was saying don't move her so much. I crawled inside the car and pulled out the other," Martinez said.
The two kids were rushed to the hospital in serious to critical condition. The contents of their car littered the street.
As for how the crash happened: the ambulance was headed east on Addison, the family's car and another were going north on Menard. A one-way street meant the two cars had to turn either left or right at the light.
"Right now it's all under investigation. All I know is our ambulance had it's lights activated with the siren and air horn going as they went through the intersection," said Deputy Chief Thomas Lynch, Chicago Fire Department.
Police are handling the investigation into the cause of the crash as thoughts to turn to its youngest victims.
"I was really praying for the baby. She looked really bad, critical, I really hope she makes it, I really do," Martinez said.