There is damage in Galveston, but not as bad as the media is reporting. They lost 17 buildings, but its a town of 60,000 people. Some areas have had flooding, but the Galveston seawall spared the town from damage by the storm surge, which flattened so many beach homes on Bolivar peninsula.
The loss of power might be a greater worry. I've been reading the local newspaper online and have seen no reports of damage at Moody Gardens, where the NRCC is now located. As phones are down, it's difficult to find out at present. Some cell phone capability has been restored. Quite a few people stayed through the storm and are there on the island now.
I'm sure they do have an emergency generator system. The whole Moody Gardens complex features a large aquarium and a rainforest pyramid with many aniimals, so they have to have a way to keep them all safe.
They certainly didn't get flattened - we would have heard about that by now, so hope that everything is OK.