Check out this video clip of an F-4 Phantom travelling at 500 mph impacting a wall designed to protect a nuclear power station (links to page with embedded QuickTime video). As you’d (hopefully) expect, the wall did its job, basically atomizing the F-4 into dust (!). Pretty wild…
Oh, and ignore the caption above the video; the audio in the report clearly states that the wall is designed to protect nuclear power plants, not withstand a nuclear blast. :-p