There was a lot of luck involved as well. It hit at 8.45 in the morning, if I remember correctly, so many would still be on their way to work. If it had happened an hour later, the death toll would have been even worse.
The bravery of the firefighters going in to rescue people when they knew there was a risk of getting killed themselves, we really don't appreciate those emergency services people enough.
Wasn't there a bombing attempt a few years before when some sheik tried to car bomb the underground car park?