Three GENIUS heads are better than one, right? WRONG!!!!
The danger of the room collapsing was due to the extra weight of the 3 of them and the soil they dropped inside, SO WHY NOT JUST THROW OUT SOME OF THE USELESS WEIGHT? They had a door that had a chasm on the other side where they could've tossed out everything in the room that they couldn't use and all they would have to do is wait for Atlantis to check in. ITS THAT SIMPLE.
I'm getting tired of the lack of intelligence these geniuses seem to have. If you want to make an episode that focuses on character development, don't get too focused on the characters because then you make mistakes such as this. THATS RIGHT I'M TALKING TO YOU, WRITERS!!!!