After 8 years of flying virtually every week, I finally got a bit of scare on my 2nd flight of the day today. At about 18000 feet, there was a brief pop and the oxygen masks came down. At first, we all looked at each other like "What are we supposed to do now?" The flight attendants honestly weren't even paying attention and didn't realize it had happened. I thought maybe it was just the first class cabin where I was sitting (upgrades are so nice sometimes) but when I turned around I saw the entire plane's masks had come down. For about a minute before they told us anything it was a bit scary, just not knowing. Then the pilot came on and said they missed an indicator in the cockpit that told them something was wrong with the heating and pressurization system and because they missed the blinking light, they weren't able to descend quickly enough to prevent the masks from coming down. So they descended quickly when they realized the issue, the masks came down and we got to put them on for the next 20 minutes while we turned around and headed back to MSP (where we came from, I was on my way to LGA). People were actually pretty calm, most put on their masks and went back to working, reading or sleeping. Kinda funny. When we got there, because they had declared an emergency landing, we were stopped on the tarmac and surrounded by fire trucks and police cars. Fun times. Turns out by policy they have to do their "drill" anytime an emergency is called, so they circled us, apparently checked out the plane from the outside and then went on their way and we drove to the gate as usual.
The masks are more annoying than they look. It was a bit suffocating despite the oxygen flowing (the bags really don't inflate like they tell you :) I certainly felt for the family that was a few rows behind me with a toddler. I kept imaging having to keep that mask on Reese or Asher (impossible no doubt). They were also unable to control the cabin temperature so it was HOT. Anyway, all is fine, we returned to MSP and they got us a new plane and took us on to LGA a few hours late with nothing but a bit of turbulence on that flight. I took some pictures to commemorate the occasion. Here's to hoping it never happens again.