It could be just wet electronics that need to dry out. An engine also needs air, I would check to see if the air filter is soaked. Before I started pulling plugs or anything else I would pull the dipstick and see if the oil on it looks normal.

With electric fuel pumps, excess fuel return lines and fuel injection vapor lock is history.

If the engine will rotate normally it has not seized. There is another reason it is not starting, very likely related to all the coolant spaying around. Check the top of the engine and see if there is any collection of coolant anywhere.

If you are able to start the engine and have not refilled the cooling system, it is imperative to turn it before it overheats again.

Unfortunately, if you ran the engine until it quit on it's own and that was after the gauge was pegged for very long you could have internal engine damage. Was the engine getting noisy before it quit?

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas