Burn marks/potential fire

Two years ago when I moves into my apartment, Xfinity came and installed my modem for wifi.  I left the modem where they put it, on the carpet in the corner of my living room.  I am now moving out and there is a black burn mark around where the modem sat. I never would have thought to check it since that's where the professional tech had put it and now come to find out that installation could have started a major fire in my home. Someone should be aware of this and I will be notifying my apartment complex as well. If I lose any part of my security deposit because of those burn marks rest assured I will be sending a bill to your home office. My family could have been seriously hurt if a fire had started.