My mid-1970's computer company caught fire and burned, for possibly as much as twenty seconds. If you're wondering, I can assure you: you never want to experience any kind of malicious fire.
In those days we used electrostatic printers. They spilled a fixer on special paper and the printer burned dots into the papers. The print stayed visible for a year or two before fading into uselessness. The fixer was nonflammable. But apparently, if a tiny leak allowed it to form a cloud over the printer's power supply, eventually it would start a flash fire. The fire consumed all the oxygen in the building very quickly, and after those first twenty seconds it probably just simmered a bit.
It was our practice to run 500 page printouts overnight, so the fire happened about 2 a.m. with no one there. The guy who left at 1 a.m. said "Gee, I wish I had been there, maybe I could have done something." Had he been there, he probably would have died.
I arrived the next morning to find mini-computers smoking in the parking lot. Firetrucks were there, and the windows were black with smoke. A new employee started work that day. He stood there looking at the mess. I would have understood if he had quit on the spot, but he stayed and worked there for four years.
The company survived the fire because, one week before, they had shipped a brace of computers and software to a prime customer. If those computers had been caught in the fire, they could not have been shipped and there would have been no cashflow cushion, nothing to tide us over until insurance money came in.
Everything smelled of smoke. There were plastic knobs in the ceiling to adjust vents, and the knobs nearest the fire now looked like stalactites. The computers closest to the fire looked just awful. But their only problem was that their plastic exteriors had melted. New plastic was put in place, and we used those machines for years.
Several Modcomp machines were twenty feet from the fire, and they worked fine afterwards. But the Modcomp company was kind enough to warn us that these computers would all fail disastrously after about three months, because the acid smoke had caused uncorrectable damage to their printed circuit boards. Their machines all failed as predicted, but there was insurance money to replace them.
We did no programming for weeks. Removable disk packs -- lots of them -- had to be opened and cleaned. Card decks -- thousands of punch cards -- had to be cleaned. Everything had to be cleaned. After about six weeks the office stopped smelling of smoke, and we started to program again.