[Jimbaugh]

Check the concrete and make sure that it wasn't below grade.

[Fred Hayek]

"Check the concrete "
One of the problems with Shoreham ( besides enviro-whacko anti-nukes) was possible substandard concrete from an alleged mob-influenced supplier. Anyhow, There isn't much you can do to have such a building hold up against a plane heavier than the 707 design criteria, loaded with jet fuel ( a 767 flying from Boston to Los Angeles would still have quite a load), and going at 400 knots (my guesstimate) instead of the approach speed of 150-200 knots. Both didn't hit in EXACTLY the same spot, but there had to be some prior determination where to hit. This implies some accomplices for technical support.