CHARLESTON, S.C. (WCBD) – The driver of a tow truck was knocked over the side of the Don Holt Bridge while responding to a crash Wednesday morning, according to the Coast Guard.

All westbound lanes of the bridge were shut down for hours after a crash was reported on the bridge at 9:49 a.m.

According to Cpl. Matt Southern with the SC Highway Patrol, “a pick-up truck struck the back of the deputy’s vehicle resulting in the deputy and the tow truck driver, who were [both] outside of the vehicle at the time. The deputy went to the hospital with injuries and the driver of a tow truck at this time remains unaccounted for.”

Capt. Roger Antonio with the Charleston County Sheriff’s Office said CCSO Deputy Mike Costanzo was sent to an area hospital with serious injuries after being struck by a passing vehicle. He said the Deputy Costanzo was assisting a disabled vehicle when he was struck.

According to Capt. Antonio, Costanzo worked at CCSO from 1995 to 2006, then returned to the agency in 2017.

The agency asked the public to pray for his recovery.

The Coast Guard is leading the search for the town truck driver. As of Wednesday afternoon, two Coast Guard boats, Marine Patrol units, and a CCSO helicopter were engaged in the effort.

Officials with the Mount Pleasant Police Department said entrances onto 526 from Long Point Rd. are blocked.

Editor’s Note: This story is breaking and is being updated as more information becomes available.