This is likely off-topic far enough to get moved or poofed - go ahead mods if it is....

Reports on that bus were that the people on board had portable oxygen tanks with them that were in use.

There is a WIDE misunderstanding of the dangers of these systems. They are in use by tens if not hundreds of thousands of patients daily, most suffering from emphasema (smoking related in most cases) and some other maladies.

Many people say that the oxygen tanks "caught fire". That's not true - oxygen doesn't burn. But it does greatly accelerate combustion, and things that would not normally burn WILL in the presence of pure - or nearly so - oxygen supplies.

A person with a live oxygen feed going from one of those portable tanks is a severe fire hazard. Any source of ignition on or near their person can cause a fire that will spread with lightning speed. An enriched oxygen atmosphere, as would exist in a bus full of people who are all using these kits, would turn a minor smoldering wire event (no big deal) into a conflageration in seconds.

I see people banging these units around in South Florida all the time with no regard at all to the potential risks involved. I don't know if its because they haven't been told, or if they just don't care. As a diver who mixes up oxygen into his scuba gas, I take EXTREME care when working with pure O2 because of the potential fire hazard -and the impossibility of putting out any fire that DOES start in the presence of pure O2 unless I can shut off the flow of gas - difficult or impossible when the supply tank is engulfed in flames.

Transporting ONE OR TWO people on supplemental oxygen in a bus with good ventilation is probably not a big deal - unless one of the systems gets banged around and starts leaking at an accelerated rate. However, over many hours if ventilation is sub-standard, or if the bus is full of people on these systems, there is definitely an enhanced risk of trouble.

This is a tragic situation but as with many there is an issue of planning (or lack thereof!) and lack of appreciation of the risks involved if the early reports - that the bus was full of folks on supplemental O2 systems - are accurate.