UPDATE (Monday):

Chattanooga Police now say the man who jumped out of the ambulance, James Moore, has died from his injuries.

A CPD release says the ambulance was actually stopped at the side of the interstate after Moore became combative, in an effort to calm him down.

That's when he jumped out of the vehicle and tried to cross the interstate.

Police say Moore jumped the concrete median and ran across westbound lanes, where he was struck by a car.

A semi-truck then struck the car that hit Moore.

EARLIER:

A 50-year-old man is now in critical condition after police say he jumped out of a moving ambulance and was struck by a vehicle.

Chattanooga Police say the incident happened a little after 1:30 p.m. Sunday.

A CPD release says the man was on the way to a local hospital when he suddenly jumped out of the ambulance, landed on the lanes of the busy interstate, where a vehicle struck him.

First responders managed to keep the man alive all the way to the hospital, where he is in critical condition as of Sunday evening.

The incident backed up Sunday afternoon traffic for several hours, with crews blocking 3 lanes while clearing the scene.

Traffic is now back to normal.

We're working to learn more details. Depend on us to bring you updates as we get them.