Follow the posts of 'PhiKapMom'. She was there.
Thanks.
A packed stadium is a very juicy terror target because of the potential of the enormous casualty-multiplier of deliberately inducing a mass panic stampede.
Set off multiple bombs in a packed stadium over a few minutes (especially in the upper decks) and thousands might die, pushed over the broken railings in a panic-driven human avalanche.
That's how I began my novel, but without suicide bombers. Instead, a sniper fired into the upper deck 90 times to induce the panic stampede.
I think even broken bottles of bleach, and screams of "POISON GAS!!!!" could turn a packed stadium into a scene of mass death, with folks piled up in the exit tunnels.