My next recollection was being on my hands and knees in the hangar floor and having difficulty keeping my face out of the rising water level. I sloshed out the large entrance to the hangar onto the ramp outside. Everything on me was rust-colored and it looked like the aircraft and hangar were the same. Then, as soon as it came it was over, but everything was totally soaked with rusty water. What a mess!! Rusty water was running everywhere.
We later discovered the source of this phenomenon. In an attempt to do required system pressure checks, at the end of the maintenance inspection, the ground crew had hooked up a jet start-cart to the aircraft. This was normal procedure, requiring the operating cart to be placed just outside the hangar. However, the aircraft was a little farther inside the hangar than normal and the start-cart did not have an extended hose installed. So the mechanics rolled the start-cart in closer to the aircraft, just within the hangar doors.
The exhaust from the gas-turbine in the start-cart was vented upward, right into the over-head fire detection system of the jumbo hangar. The hot exhaust set off the fire suppression system. That caused all five industrial Chrysler V-8 engines and pumps in the fire-suppression system to quickly crank up and empty the entire contents of the huge water tank adjacent to the hangar in about a minute's time.
The system worked like it should. It is a miracle there were only a few minor injuries. However, the entire avionics suite had to be removed to the shop and cleaned and dried out. I don't think we ever got all the rust deposits out of the nooks and crannies of that particular aircraft. All three station hatches were open. It took several weeks to dry everything out and inspect and repair as required. I'm not sure what did more damage, the water or the metallic rust deposits.
I had to trash everything I was wearing that night. It took over a week to get the metallic taste out of my mouth. Curiously though, I don't remember ever seeing this incident written up in safety magazines or addressed in safety lectures. It should have been.