Atlanta police aren’t sure which rider in a formation of more than 50 motorcycles ran over and killed a man Saturday morning.

The accident happened about 11:30 a.m. on Moreland Avenue at East Confederate Avenue. Police shut down the southbound lanes of Moreland Avenue for about 30 minutes.

A motorcycle serving as an escort was passing the formation in the right lane when it struck another motorcycle that had drifted into the right lane, Officer Lukasz Sajdak, a spokesman for Atlanta police, said.

The domino effect led to more collisions and a man was ejected from his bike. He landed in the roadway, where another rider ran over his body, Sajdak said.

Though he wasn’t breathing, emergency medical service workers responded and performed CPR.

Police said he was dead shortly before noon.

Two other riders were taken to the hospital with non-life-threatening injuries and a third complained of arm pain but did not go to the hospital. All four motorcycles were significantly damaged, police said.