The Atlanta Track Club expected rain. What club officials weren’t sure about, but had to deal with at The Atlanta Journal-Constitution Peachtree Road Race, was lightning.

A lightning strike was recorded four-tenths of a mile from the start area around 8:20 a.m., just before the start of the “M” time group. There are 21 lettered time groups, of which M is the 12th. Participants still in the start area around the intersection of Peachtree and Lenox roads were directed to take shelter either in Phipps Plaza or Lenox Square or their parking decks.

Race director Rich Kenah said there were roughly 25,000 participants who waited out the lightning, with the runners on the course allowed to continue. The race’s alert level, which began at yellow (moderate) due to the rain, was raised to red (high). The awards ceremony in Piedmont Park was canceled.

“Safety is No. 1 for us,” Kenah said.

After runners were sent back to the starting line shortly after 9 a.m., the remainder of the race was conducted without serious incident, despite the steady rain. Kenah said that longtime staff and volunteers could not remember a lightning delay in the race’s 46 years.

He gave credit to track club staff, the race’s 3,400 volunteers and the assistance of the city of Atlanta, and city firefighters and police officers.

“To pull the world’s largest 10K under these conditions is something that I as the race director am very proud of and Atlanta should be proud of,” Kenah said.