Originally Posted by
TFlyguy
The rapid beeping sounds like a toilet smoke detector
I had wondered that as well, I don't have experience on Sukhoi bit have flown A330/380 B777 and it also sounds similar to Airbus but could also be the lav. Did seem a tad early for signalling system to be activated unless it were the Art crewmember doing so as he would have known much sooner how serious it was.
But lab seems more likely given the timing.