Lots of factors here. If you were on or near the bus and actually didn't die and weren't seriously injured then you'd be fine even empty handed and buck naked. It was outdoors and during the day. Plenty of ventilation and light. On the subway, however, a mask rated for smoke filtration and xenon-type light would have probably been helpful. As for myself, I carry no such mask or light at this time (may change in the future) so I would have had to make due with my photon II for light and cotton cloth for an improvised mask. Depending on the specifics of the situation, a Leatherman-type tool and a trauma-rated FAK (and the knowledge to use it) may have also been quite useful. I dont EDC either of those either.