Two skydivers were injured in a mid-air collision that left one of them with a concussion.
The men, both licensed skydivers, collided with each other on Tuesday near Ottawa, Illinois, about 40 miles southwest of Aurora, a spokesperson from SkyDive Chicago confirmed.
One skydiver was knocked unconscious, but was saved when his automatic activation device, a backup mechanism, automatically opened his parachute, the spokesperson said.
Both men made it to the ground safely, with one landing at the Ottawa Airport and the other in the Fox River, according to the Ottawa Fire Department. They were rushed via ambulance to a nearby hospital, where one diver was diagnosed with a concussion.
Skydivers are not required to use an automatic activation device but experienced skydivers urge jumpers to use them.
The accident happened as hundreds of divers took part in Skydive Chicago's Summerfest this week.
It was the only reported incident out of the thousands of jumps that have taken place thus far, according to the company.
ABC News' Ryan Burrow and Jenn Leong contributed to this report.