It happened just before 9 a.m. on Henry Hudson Parkway West, over Kappock Street near Independence Avenue in Riverdale.
The front portion of the BxM1 bus along with at least one wheel was dangling over the edge.
MTA Express Buses are 45 feet long.
Debris was knocked into the roadway on Kappock Street.
There were no passengers aboard the express bus which had just started its run into Manhattan.
The driver couldn't make it around a parked car on the service road of the Henry Hudson Parkway.
Another bus driver stuck in the ensuing traffic a few lengths behind offered to help his colleague and got behind the wheel.
The driver passed the parked vehicle, got on the curb but between grass and ditch, he lost control of bus and hit wall.
The 37-year MTA veteran was not hurt, nor was anyone on the ground below.
Two tow trucks were used to pull the vehicle back onto solid ground.
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