​​This information is preliminary and subject to change.

​On August 19, 2025, about 0122 local time (eastern daylight time), the research vessel Go Justice was transiting the Saint John’s River when its mast struck the underside of the John T. Alsop Jr. Bridge (commonly known as the Main Street Bridge) in Jacksonville, Florida. Five crewmembers and three contractors were aboard. The vessel's mast was damaged, and the bridge sustained damage to its electrical system. The Main Street Bridge remains inoperable but is open for vehicle traffic. There were no injuries and no pollution was reported. Damage to the bridge is estimated at $2.1 million. The Coast Guard has declared this incident a major marine casualty. The Coast Guard will lead the investigation, and the NTSB will investigate and determine the probable cause.​