Chicago officials responded to reports of explosions at Soldier Field around noon Saturday.
According to the Chicago Fire Department, a tent that belonged to a sponsor at the scheduled Autism Speaks Walk event Saturday caught on fire and caused a propane tank to explode.
A Facebook video posted by one of the participants at Saturday's event shows a white tent on fire.
Authorities said a 60-year-old man was transported to Northwestern Memorial Hospital for smoke inhalation and is in good condition.
No other injuries were immediately reported.
Police and fire officials are still investigating the explosion.
