2000s Movie about creatures coming from Basement drain of Apartment Building

Question

Guy comes to visit with his sister that he hasn't seen for years. It's Christmas time and her husband doesn't want him there. One of the kids goes to the basement to ride her trike. The basement drain has coughed up creatures that look like horseshoe crabs. Sis and hubby go to a Christmas party.

Other kid goes to the basement to find their sibling and is being hunted by a creature that has eaten the other kid. Uncle goes to find both kids and finds the creature that is hunting the kid. Meanwhile a creature crashes the Christmas party and the next thing you know the people in the apartment building are fighting to get out of the building only to discover that there are fiery fissures and creatures opening everywhere and the world is under siege.

Answer 1

This is probably the 2009 film, The Blackout.

it's Christmas eve and westphalia is under quakes and severe high temperatures with power surges going around the city( Los Angeles that is) . Scientists can't figure it out. There's a Christmas party in a tenement block, and the couples presented are living in the same building - 1 family (man + woman + man's brother + 2 kids boy and girl) , 1 about-to-get-divorced-couple, 1 about-to-get-married-couple, and some random dudes and girls. The newsman tells the power-surges are connected with the temperature and the quakes.

Mom and dad are trying to have fun(in bed) but the kids find them out and they get sent to the basement to bring up their presents. Nasty creature eats their guts.

There's an agoraphobic guy at the 2nd floor, friend with the superintendent and the electrician, and he's a master in discovery channel and electronics and communications. Electrician "Ralph" gets torn to bits. The party is ruined, more creatures come and claim lives. Some guy's brother tries something he saw on TV ("Hey the creatures might be photosensitive" ) but he gets a big head-shot and dies. The little girl is not dead - apparently she managed to survive ( somehow I have no idea ) and she got in a defunct elevator ( again HOW is a big question ). The group manages to kill 2 creatures, find out the main building entrance is blocked and head for the roof. They go through that defunct elevator's shaft and find out the little girl.

There is a better (but still critical) review here that includes some still image including the creatures.

Trailer

I think found with a search for horror film Christmas basement creatures, which led to this Bloody Disgusting list of Christmas horror films, wherein I searched for "basement".