 The Peachtree is a 4th of July tradition in Atlanta. This year's race, the 55th Peachtree, had about 50,000 runners, walkers, and wheelchair racers. But the Atlanta Track Club canceled the event towards the end due to extreme heat. Race organizers said those still on the course could complete it, and they'd still have water and first aid, but they'd no longer record official results. This happened about two hours after the last wave of contestants started, so most participants would have already been done.