Chipley, FL – Authorities say six children and two adults in the Florida Panhandle are in serious condition after carbon monoxide filled their vehicle, causing them to fall asleep.

Washington County Sheriff Kevin Crews tells the News Herald the incident happened Tuesday afternoon north of Panama City. He says emergency responders found some of the children unresponsive inside the vehicle. They were revived on the way to the hospital.

Crews says the group was driving in deep mud when the vehicle began filling with carbon monoxide.

Authorities didn’t release the names of the victims.

No further details were immediately available.