I find this interesting. It happened during the San Francisco earthquake of 1906 (BTW: very few gun control laws at the time and the mayor felt he had to issue this statement):
..from the 1970s to the present day there have been occasional large-scale community crises after which researchers studied mass looting. One was the 1977 New York City blackout during which selective neighborhoods experienced massive looting illustrating the distinctive conflict situation pattern found in the 1960s. However, before “obvious” implications are drawn, one should note that similar blackouts in 1968 and in 2003 did not generate mass looting.
Many times looters do not loot in places that have not been evacuated also. So tying in gun laws and looting is not neccesrily an easy thing to do.
Following the disaster, democracy disappeared; city and military officials took extreme action to control the chaos that enveloped San Francisco. Mayor Schmitz issued his infamous proclamation: an all-city curfew to expand police power to "shoot to kill" any looters.