It's wrong to put peoples lives in danger.
Jay sees a bus speeding down the street on a collision course with Marty.
Jay wants to stop Marty from getting hit.
Jay jumps toward Marty pushing him out of the way but putting himself in danger of getting hit.
Jay pushes Marla who is next to him into Marty which knocks Marty out of the way but Marla is now in the path.
Marty is eternally grateful.
Marla gets hit by the bus.