SEATTLE -

The National Transportation Safety Board is meeting to determine the probable cause of the 2015 crash of a Ride the Ducks vehicle that left five people dead and dozens injured.

The amphibious passenger vehicle was traveling north over the Aurora Bridge on State Route 99 in Seattle when it crossed the center line into the southbound lanes.

Duck 6 hit a charter bus full of college students, killing five and injuring people on both vehicles. Three other vehicles were damaged in the crash.

An NTSB preliminary investigation said the Duck boat's axle failed.

The NTSB will meet in Washington D.C. on Tuesday to review the evidence collected in order to learn what likely caused the crash.