Seven people were taken to area hospitals in serious-to-critical condition after a car crashed into a tree about 1:30 a.m. on the South Side, according to authorities.
One of the men in the car, a 28-year-old from Chicago, died at Mount Sinai Hospital, a spokeswoman for the Cook County medical examiner's office said.
The accident, at Hamilton Avenue and Garfield Boulevard, required a pin-in response and an Emergency Medical Services Plan 1, which bring extra ambulances and fire department equipment to the scene, according to the Chicago Fire Department.
The people injured were taken to Mount Sinai Hospital, Northwestern Memorial Hospital, John H. Stroger, Jr. Hospital of Cook County, and Advocate Christ Medical Center, Chicago Police Department News Affairs Officer Amina Greer said.
All four hospitals have trauma centers.
The CTA is rerouting buses in the area, according to the agency.
It's not yet clear what caused the crash.