'We're not over land': WestJet passengers recount emergency landing in smoke-filled cabin

Different incident: In an e-mailed statement Porter Airlines said the aircraft in question, Bombardier's Q400, operates below 25,000 feet and is therefore not required to have drop-down oxygen under regulations administered by Transport Canada and the Federal Aviation Administration in the U.S.

https://www.theglobeandmail.com/news/national/porter-plane-that-filled-with-smoke-had-no-oxygen-masks-passenger-says/article26915151/

I don't think the Q400 has supplimentary O2. That's why they have a max altitude restriction.

They weren't deployed because they shouldn't be deployed. Uneducated statement by passengers and media.

The masks are partial rebreather-style masks, so when you take a breath, the mask brings in cabin air as well as oxygen from the system. It's dangerous to use the mask in this case because of the risk of breathing in smoke. A constant flow of oxygen into the cabin would not be good.

It looks like the cabin and flight crew did a great job. I love the way the media cherry picks one person who comments on the lack of oxygen masks. I'll bet that 20 other pax commented on the excellent job that the crew did, however these comments are seldom deemed newsworthy.