UPDATE: The Florida Highway Patrol says a mechanical steering failure caused the truck to veer off the road, into the marsh 45 feet below. The driver is in stable condition at Tampa General Hospital.
Emergency crews are on the scene along I-75 in Riverview, where a truck hauling a bulldozer crashed off a bridge and onto the banks of the Alafia River.
According to the sheriff's office, the flatbed wrecker was headed south on I-75 when the driver lost control and crashed into the riverbed.
The truck came to rest in a muddy, marshy area 45 feet below the bridge and is not underwater.
Photos from the scene show skidmarks and the damaged concrete wall on the road above.
The view from SkyFOX showed the truck broken into pieces, with the cab in one spot, and a set of wheels in another spot. The bulldozer appeared overturned, stuck in muck.
The driver, 29-year-old Jeffrey Cook of St. Augustine, was rescued by a Hillsborough County deputy and an off-duty reserve firefighter. Authorities say Cook was seriously injured.
One lane of Interstate 75 southbound will be closed while crews work to remove the truck and the bulldozer. In the meantime, traffic along I-75 is backed up for miles.