Three men have died within 16 minutes of each other while running a marathon in Detroit.
The Detroit Free Press, which sponsored the event marathon, reports that they collapsed and died.
Autopsies for the three men are complete, but it is still not clear what caused their deaths.
The Wayne County Medical Examiner's Office is submitting tissue and blood for further testing.
The marathon is an annual event in its 32nd year. The only other recorded fatality during the event was in 1994 when a runner died of a heart attack.