Chris,
Excellent point for concern. I didn't include a comment that these towers were around 70 years old. Properly designed, built and maintained, this fact should have little if any difference in keeping them standing. Conversely, inadequately maintained could have resulted in them being weakened by corrosion. Incidentally, the WLW radio tower that handled the station's 500 kW transmissions and that was built in the 1030's still stand gloriously about 1 1/2 miles from my QTH. This tower literally rocks on a ball-to-ball pivot at its base and is held erect by several large guy wires. It truly is properly maintained.
This makes me nervous, because a cornerstone of our argument about setbacks in antenna cases and ordinance negotiations are that towers typically fall within a narrow radius around the base of the tower; a small percentage of their height. These towers most certainly did not do that, but that may be due to the fact that it was a three-tower DA. Not sure.
And the towers were "windmill" type, too. Not a design that one would think would collapse near the base and fall laterally.