Out of curiosity, I did some research on various towers I know about or have visited in the past. In looking through the on-line after-Katrina satellite photos, I was able to find a few that appear to have survived, quantity if not quality:
WWL AM 870, upper right corner of photo:
http://ngs.woc.noaa.gov/storms/katrina/25215839.jpg
WSHO AM 800, left center of photo:
http://ngs.woc.noaa.gov/storms/katrina/25215135.jpg
WDSU-TV, WRBH FM, upper left of photo:
http://ngs.woc.noaa.gov/storms/katrina/24715446.jpg
WYLD-FM, top of photo:
http://ngs.woc.noaa.gov/storms/katrina/24713988.jpg
WWL TV, WWNO-FM:, top center
http://ngs.woc.noaa.gov/storms/katrina/24442138.jpg
WLNO-AM, left center, damage visible:
http://ngs.woc.noaa.gov/storms/katrina/24528010.jpg
I looked at WSMB also, they looked OK (towers standing) as far as you can tell from these views.
WWL AM 870, upper right corner of photo:
http://ngs.woc.noaa.gov/storms/katrina/25215839.jpg
WSHO AM 800, left center of photo:
http://ngs.woc.noaa.gov/storms/katrina/25215135.jpg
WDSU-TV, WRBH FM, upper left of photo:
http://ngs.woc.noaa.gov/storms/katrina/24715446.jpg
WYLD-FM, top of photo:
http://ngs.woc.noaa.gov/storms/katrina/24713988.jpg
WWL TV, WWNO-FM:, top center
http://ngs.woc.noaa.gov/storms/katrina/24442138.jpg
WLNO-AM, left center, damage visible:
http://ngs.woc.noaa.gov/storms/katrina/24528010.jpg
I looked at WSMB also, they looked OK (towers standing) as far as you can tell from these views.