JACKSONVILLE, Fla. -- A 76-year-old is dead after his vehicle ended up in the St. Johns River early Friday morning.
The Jacksonville Sheriff's Office said a witness at the south bank boat ramp in the 1000 block of Museum Circle Drive saw a van go into the water around midnight.
Off-duty officer, Mark Muchowicz, who First Coast News has learned lives in the San Marco area and was on his way home from a side job at a local hospital, heard the emergency call go out and responded to the scene.
JSO said Muchowicz risked his life and dove into the river with special tools that can be used to help free 76-year-old Thomas Franklin Wester from a sinking vehicle.
He then put them to use and was able to bring Wester to the surface. According to JSO, Wester was found in the van's driver's seat as the vehicle took on water and rotated upside down.
By then, additional emergency personnel had arrived and began performing CPR on Wester before rushing him to Baptist Health in San Marco, where authorities said he died.
The JSO dive team also responded to the scene and searched the water for other vehicles and individuals. A source close to the investigation told FCN nothing else was found.
So far, it's unclear how the van ended up in the river.
A lieutenant said the investigation is ongoing by traffic homicide detectives, but that it could have been an intentional act or the man could have suffered a medical episode.