This happened in Paris last week apparently:
Although mall are dying left and right in the U.S. the rest of the world seems to still enjoy the concentration of stores in one location.
If for no reason the mall’s doors close down and the escalators stop working, yours truly (if not already out) would scramble to an emergency exit in a very expeditiously manner or at worst, find a secure & defensible position with good cover and wait for shit to either calm down or hit the fan.
And return fire if required.
PS: Regular people seemed to think it was unexpected, interesting and non-threatening.
That’ how they get killed.
If in the US, security cameras would be counting double digits how many were pulling pistols and diving behind planter boxes. Yeah, those "no guns allowed" decals really work, eh? Time for a social experiment. How many choose to pull spouses with them, or send them away to "safety," or simply abandon them. Gee, maybe we should try it!
Once outside, I'd get to my vehicle and GTFO!