Officials with the Chicago Marathon say one man suffered a cardiac arrest near the end of the race and nine others were also hospitalized.
Race medical director Dr. George Chiampas says the 47-year-old man was alert and talking on Sunday after being shocked twice. He declined to say where the runner was from and wasn't sure if the runner had a previous heart condition.
The annual race winds for 26.2 miles through different Chicago neighborhoods. The runner suffered the cardiac arrest around the 21st mile.
Chiampas says at least nine other runners were also been taken by ambulance with injuries or ailments, although none were life-threatening.