I'm so glad everyone--you, your brother, and, of course, Loki--is okay and also that none of your stuff was taken. It would be really disconcerting for me just knowing that some stranger had been in my house while I was sleeping--very creepy. Not a nice feeling at all!
Coincidentally, my grandma's house was broken into yesterday while she was out visiting my grandpa at the Extendicare--a couple of teenaged kids have been performing opportunistic daylight robberies in the area, apparently. They threw a brick through my grandma's back window to get in and took her good jewelry, but not really anything else--they obviously knew what they were looking for. The robbers were on foot (someone saw them running up the street with the jewelry box), which, luckily, limited the number and kinds of things they were able to take, but she's pretty upset; my great grandmother's wedding ring was apparently one of the things that was stolen, and you can't really put a value on something so sentimental.
I definitely understand your anxiety about Loki getting out or something happening to him as a result of the break in; as soon as I heard that my grandma's house had been burglarized while she was out, I asked if Jack, my grandma's cat, was okay--he can be a bit of a door-dasher, and I was worried that he might have left through the broken window. My grandma found him hiding under the kitchen sink (he must have run over, opened the cupboard door, and hid himself there when the brick came through the window); he was shaken, but otherwise fine.