I say we hit the cruise control

So I am having a little freak-out attack right now. Here's the story: I woke up this morning at about 9 and went to the bathroom. The light would not turn on. I checked other lights upstairs and they were all fine. I went downstairs to check the fuse box and the hall light downstairs was out. I heard the cat meowing and realized she was locked in the laundry room. I let her out and tried to turn on the light there but it was out. So I got a flashlight and went back to the laundry room to check the fuse box. I couldn't see any fuse wrong so I called my mom and left a message. She called a while later. She said she blew the bulb in the hallway downstairs this morning and maybe that blew the fuse. She said she said bye to the cat upstairs so she had not locked the cat up. I had heard Cari up around 7:15 and so I figured she couldn't turn on the bathroom light and probably went downstairs and accidentally locked the cat up. Cari just woke up and said when she was up this morning earlier, the bathroom light worked fine. She went back in her room and the cat followed her in there. The cat left her room a little while later and she closed her door. She never went downstairs.

So, my dilemna is how did the cat get locked up? And, if my mom blowing the bulb downstairs did not blow the fuse, how did the fuse blow? This is very scary. It feels like there had to be someone in this house...scary...