We had one here about 18 months ago that was 7.5+ nobody died. It is all in the building codes
http://www.ibtimes.co.in/7-1-magnitude-earthquake-hits-pacific-island-guam-no-tsunami-alert-609291
They lowered the strength to 7.1
The damage is also affected by the depth of the quake, as well as the land structure.
Some EQ’s leave devastating damage with a 5.1 quake. We had one in my area but only minor damage happened, mostly some cracks here and there.
I watched my walls and balcony rise up and down as well as shake side to side, but the worst damage in the building was the kitchen sink areas pulling from the walls a little, just enough to split the calking, and raise a few nails on the steps leading up to the balcony. And this is an old building, built in the 50’s and not for an earth quake prone area.
So ya, many different factors affect the types and severity of damage even at the same rating.