You can tell right off the bat from the inconspicuously placed coffee mug.

So the real story behind this is basically used as warning to any welders using oxy-acetylene. During a cold, unspecified time of the winter, a welder was running low on acetylene due to the cold temperatures which makes, on a molecular level, the gas so inactive that it doesn't have enough pressure in itself to come out of the cylinder. Kind of like a how a basketball wouldn't be as bouncy if you put it in a cold place. The welder thought it would be a good idea to warm up the cylinder just to make one last use of it before having to replace it. It's a great idea, that is if you do it properly by placing the cylinder in a safely warm room/area. The welder, however, thought that he could simply use the available burning gas to heat one side cylinder to make it work. Amazingly enough, it worked... for a while. Because of the cold weather, the sudden heating from the torch caused a heat distortion in the metal of cylinder which made it weaker. In other words, imagine a balloon getting a weakening spot on one side that eventually made it pop. Now imagine the same concept, but this time the balloon is made of solid steel. In the end, the welder survived the pants-shitting explosion unscathed, only to be reminded by the loss of an acetylene cylinder that must have cost at least $200.

Fanboys belong to  greyofpta
Exploded cylinder belongs to the College of Siskiyous Welding Class
Picture by me.