I posted some things on Reddit about it, but I'll summarize here. There are a lot of alarmist people posting about how they're sure the town is "uninhabitable"

I posted some things on Reddit about it, but I'll summarize here. There are a lot of alarmist people posting about how they're sure the town is "uninhabitable" and that it's being "covered up". The truth is that the people handling the derailment and fire made some very tough calls to avoid an explosion that might have leveled half that town or exposed hundreds to thousands of people to a carcinogenic chemical. They chose to burn off the chemicals to avoid the explosion. People are scared by the dark cloud and by the smells, and that's understandable. But the burning does seem to have eliminated much of the chemicals on site, and none of the air testing that's being done to look for combustion products or gaseous Vinyl Chloride is finding any. There are pictures of people walking near the destroyed railroad cars now, with no hazmat suits. Vinyl Chloride has a half life in the atmosphere of about 20 hours. It decomposes into CO, CO2, HCl and trace Phosgene (a tiny fraction of a percent). Any Vinyl Chloride Monomer released into the air or soil will be decomposing into acid (once the HCl mixes with atmospheric water) and that acid will have a somewhat higher (weaker) pH than household vinegar. At least with regard to the Vinyl Chloride monomer tanks, the authorities seem to have done the right thing. If they managed to burn off the other tanks, those chemicals create even fewer toxic combustion products - carbon monoxide is basically it. The dark cloud is probably coming from all the other stuff that burned or partly combusted due to that very hot fire... paint on the rail cars, plastics in the box cars, whatever else was in the box cars, railroad ties that caught on fire, and chemicals outgassed from nearby objects exposed to that amount of heat. It's probably not something you'd want to breathe, but it's also not the "cloud of death" that's being clamored about by the conspiritards. Both the air test reports and the pictures of people without masks walking on the site now show that it's likely the burn off achieved the desired effect. Within a few days the dark clouds will dissipate like any other smoke, and people will finally calm down. It's still an awful situation for anyone whose home got covered in smoke or whose animals died due to the derailment or fire, but it's not an apocalypse.