We've all seen planes flying over Caleta on their approach to the Airport. They are at landing speed, about 175 mph. Cruising speed for a Boing 737 is about 500mph.
The planes crashing into the Twin Towers were travelling at FULL SPEED. Next time you're by the Chinese shops at Matorral, and a plane comes over to land, imagine it travelling almost 3 times faster and smashing into a building. The mind boggles. RIP all those that were killed.
NO LANDING GEAR DOWN-TRAVELLING AT FULL SPEED
(http://img6.imageshack.us/img6/4840/1h5l.jpg)
I remember watching the second plane crashing live on tv and worrying about my friends who were living in the area at the time. Such a terrible day.