WASHINGTON, DC -- A civilian runner died Sunday during the Army Ten-Miler 10-mile race. According to media reports, the unidentified runner was about 200 yards from the finish line at the Pentagon. When the race began, it was unseasonably warm at about 70 degrees with high humidity.

The Association of the US Army and KBR were the co-lead sponsors for this year’s event. The 23rd annual race attracts more than 26,000 runners of varying experience from around the world, according to race officials. The race begins and ends at the Pentagon and passes national landmarks such as the Lincoln Memorial, the Washington Monument and the Capitol.

Also on Sunday, a runner collapsed and died while competing in the Chicago Marathon, which also had high heat and humidity. Chad Schieber of Midland, Mich., 35, collapsed while running on the South Side of Chicago. He was pronounced dead shortly before 1 p.m. at a local hospital. The 88-degree temperature was a record for the Chicago Marathon.

An autopsy showed that Schieber died not from the heat but from of a heart condition that he knew he had prior to running in the marathon, according to one media report.