Cool, literally. Here is what I can observe from the videos. As any of you who have attended my training sessions you would have recognized the term perlite. This is a type of insulation made from crushed volcanic rock then fired in a kiln to get it to expand like popcorn. Perlite is non-hazardous, but a real dust problem. Perlite tanks have a pressure relief device located on the top of the tanks that looks like a little hat. This is called a lift plate and is held in place by the tank vacuum and protects the outer vessel which is not a pressure vessel from pressure build up. A super insulated also has a outer vessel pressure relief device called a rupture disc and these are typically located on the bottom of the tanks. Again from my training you might remember several pictures of ruptured tanks that did not have adequate outer jacket protection. When a lift plate first pops off of a tank due to over pressure it will look like a volcano spewing ash. If you observe this the first thought that goes through your mind is OH SH--! I know this from experience. In the video the white plume that you see coming from the top of the tank is vaporized oxygen. From the those videos (and not the news reporters that don't have a clue) I am going to assume that you had an internal line failure. Ii will also make an assumption that the failure was in the piping near the top of the tank. If the failure was in one of the lines near the bottom the bottom of the tank the bottom would be heavily iced and they should have water spraying on the bottom of the tank to keep it warm so that the carbon steel outer jacket does become brittle and fail due to low temperature.