Vapor lock, will cause rough running and die outs.
The battery go out, the oil or gasoline gone, carborator, filter, a whole lot.
You can blow a head gasket or the head can crack or be warped.
My 2007 overheated and the engine shut down automatically - while I was driving
The engine overheats and parts can melt, crack, even explode (massive expansion due to heat.)
car overheats and produces steam/smoke. may crack engine block or head.
If gasoline is used in a diesel it will damage the engine. If diesel is used in a gasoline engine it will do no real damage as the engine will not run.
Worst case scenario--the engine has seized and you are going to be buying a new one.
it turns into a liquid
It will ruin the engine. Ethanol is a much harsher fuel than gasoline and also requires a higher compression ratio to burn efficiently.
behind the engine cylinder
Often this happens when a tune up hasn't been done on the car in a long time. It also may happen when one of the cylinders misfires or when the engine overheats.
What happens is you must remove the petrol immediately. Petrol or gasoline will destroy a diesel engine.