Family and friends of three half-marathoners who died during the Detroit marathon say the runners had trained for the race and were unsure what could have caused the deaths.

Autopsies are scheduled for Monday.

Officials say 36-year-old Daniel Langdon collapsed at about 9:02 a.m. Sunday between the 11- and 12-mile markers and 65-year-old Rick Brown collapsed at 9:17 a.m., near where Langdon went down.

Officials say 26-year-old Jon Fenlon collapsed at about 9:18 a.m., just after finishing the 13.1-mile half-marathon in 1:53:37.

Laura Fenlon tells The Detroit News her son had always been an athlete and she did not know of any medical problems he may have had.

The deaths mark the first fatalities at the Detroit Free Press Marathon since one runner died in 1994.

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