Sites Inforwars, ZeroHedge, Russia Today, and even the UK's Daily Mail all posted about the explosion and related worries about a potential nuclear disaster.
The video, which has been viewed over 2.6 million times can be seen here:
From Youtube user
ZeroHedge reported that the explosion could be seen from space and posted this picture as "proof".
The truth is somewhat less cataclysmic.
The video is of a real explosion, a normal non-nuclear bomb fell on a chemical factory. The image promoted by ZeroHedge author Tyler Durden was actually taken by astronaut Terry Virts from the International Space Station, and is nothing more than a sunrise. You can see Terry Virts' Twitter posting of the image here.
While the Daily Mail mentions that some were concerned about it being a nuclear explosion, the article clearly states, "A giant explosion which rocked the Ukrainian city of Donetsk sparked fears of a 'tactical nuke' after pro-government forces shelled a rebel-held chemical plant."
Not to mention that if it was a legitimate nuclear detonation, radiation detectors all over eastern Europe would have picked up on the very telltale signature of a nuclear explosion and news organizations the world over would have been reporting on it. Let's not forget that this is Ukraine, home of Chernobyl.
Neither the size, nor brightness of the explosion were indicative of it being a nuclear detonation - tactical or not. This was just another example of pro-Russian propaganda. Conspiracy theorists tried to spin it as 'the poor ethnic minorities seeking freedom have been nuked by the evil pro-Western Ukrainians'. In reality, they've successfully shown they have succumbed to "nuclear foot-in-mouth disease".
A bit of advice: sites like InfoWars have absolutely no credibility so ignore them and use some common sense.
For the record, mushroom cloud explosions are not the sole domain of nuclear annihilation. In fact, any adequately large explosion will result in a mushroom could.
Here's a video of a fertilizer plant explosion in Waco, Texas. You can see the main explosion from time index 1:22.
Jacob Bogle, 2/10/15
H/T to Laura Bohling and Tom Puschak for bringing this Internet rumor to my attention.