Your kind of going over the top about this, don't you think? "Bomb" "explosion" etc. etc. etc.
It was a fuel leak. It's no longer leaking. The fuel that did leak, has been cleaned and evaporated. Call SFPD parking and make a vehicle abatement complaint, they'll put a 72 hour notice on it and it'll be gone before you know it.
Or don't do anything and wait, knowing SF it will be towed soon anyway. No matter what you do, try to relax on the hyperbole. It aint a bomb, it's a motorcycle that used to have a fuel leak. :lol