DETROIT – The westbound lanes of I-94 at the I-75 junction were shut down for nearly five hours Friday night.

Investigators from the Michigan State Police, Detroit police and the Wayne County Sheriff's Office filled the highway after a Wayne County deputy opened fire on an inmate in a moving ambulance.

ORIGINAL STORY: Wayne County deputy fatally shoots inmate on I-94 near I-75 in Downtown Detroit

The deputy was a veteran with the Sheriff's Office and was in the private ambulance guarding a 23-year-old man who had just left an area hospital.

The deputy wasn't driving, but was there to make sure the inmate would get to the downtown jail. Before they arrived, something went wrong.

It's unclear if the man tried reaching for the deputy's gun or was attempting to escape the moving vehicle, but county officials said a violent struggle started between the inmate and deputy in the back of the moving ambulance.

It's unknown how long the struggle lasted, but it ended with the deputy firing a fatal shot.

Multiple agencies are investigating to find out how the inmate got into a position to fight the deputy. The normal protocol requires inmates to be restrained and secured. There Sheriff's Office's internal probe aims to determine if that happened and if not, why? And if the inmate was secure, how did he break free?

MSP and DPD's homicide division are handling the death and the events from the hospital up to that deadly shot on the freeway.