Sadly, it seems the worker didn’t survive the explosion inside this confined space. It’s not clear exactly what the worker was doing or how the explosion happened. Theories:
While welding the worker cut through his line causing the flame to travel up his tubing and ignite his pressurized oxygen tank;
The worker was welding when a spark from his oxygen torch set off a pocket of gas that had somehow formed inside the confined space;
His oxygen tank exploded while he was welding either because it was faulty or because the temperature or pressure inside the space was too high; and
The worker was using a process called “lancing” to free up a jammed tooth, i.e., chunk of metal, that instead of just “popping” away shot off with great force and went through his chest.
The Moral: What is clear is that working inside a confined space is extremely dangerous especially when performing hot work.