[Major Matt Mason]

Unless the glass in those lower rooms is busted out, like they were in the shooter's suite, then I doubt that is gunfire.

[glenduh]

But... trip advisor
Mar 06, 2008, 11:49 AM
Mandalay Bay also has those little “ventilation strips” that you can slide open if it’s the phobia about air

https://www.tripadvisor.com/ShowTopic-g45963-i10-k1793764-o10-Windows_opening_do_any_strip_hotels_have_windows_that_open-Las_Vegas_Nevada.html