Traffic on I-85 was backed up for miles Friday afternoon after a collision involving two church buses carrying children, according to Channel 2 Action News.

The accident happened on northbound I-85 south of Steve Reynolds Boulevard. A total of 15 people went to the hospital with minor injuries. Most of those involved were between the ages of 10 and 15.

The three vehicles—all from a Catholic church in Ocala, Fla.—had been traveling in a single-file caravan when roadway debris sparked the accident. The lead vehicle, a truck hauling a trailer, swerved to avoid the debris. A church bus followed suit but was struck by the third bus.

The caravan was heading to the Civic Center on Sugarloaf Parkway.

A bus from Georgia's Hebron Baptist Church arrived on the scene to pick up the remaining passengers.