It is even funnier to have a big roommate. She exercises and does yoga in the upper bunk every day. Here comes the interesting thing. One night, she did yoga in bed as usual. She did a good job. The dormitory lights out immediately, so maybe she is tired. Then, she may just want to relax. She fell backwards from her sitting position, and then rolled down the bed ladder, or jumped down step by step. Step by step down the bed ladder, she jumped down with her back on her back. Another unsuspecting roommate shouted, "Earthquake!" And I got out of bed soon.