I was on a United flight from Chicago to Spokane about 25 years ago where we lost cabin pressure at 35m’ and the O2 masks in the plane did not deploy. The pilot put the 737 in a dive and we went downhill for 15 minutes. He leveled out between 5m’-10m’ and then we eventually landed at Billings, MT. The whole fire department was on the runway when we landed. A few of us got flights out to Denver. The rest spent the night in Billings. They flew another plane in the next day. It made the national news.
FWIW, 15 minutes to descend from 35,000 feet to a breathable atmosphere is a very gentle descent by emergency standards. That’s a little over 2000’ per minute.
My buddy who flew Lear’s for a living until retiring spoke of his one and only ‘sudden’ decompression: he was flying a medical patient from the Bahamas up to NY. They were up there over 40,000’ ASL. Some sort of air pressure valve that pushes compressed air thru a transfer fitting failed, and the cabin air was rapidly escaping.
They had to rapidly descend to a FL so the patient could breathe, but that put them in a tough spot due to the increased fuel consumption at lower altitudes.
He said they landed in VA with a little less than 10 minutes of fuel remaining, FAR into his 45 minute reserve.
Yikers.
And yeah, he already had his mask oni since they were flying well over 40,000 feet ASL.