Here's my engineering public service announcement for this week: mind your roof!
There's over three feet of snow on the ground here in Baltimore, and at least that much on any flat-roof structures in the area. Remember that the B+O Railroad museum roof collapsed several years ago under even less snow. Check the guidelines below for advice about avoiding roof collapse from snow and ice loads.
Snow loading roof collapse
Snow ice accumulation on roofs
Disclaimer: this post should not be used as a substitute for professional engineering advice. This blogger assumes no liability for any damages or loss of any kind that might arise from the use of, misuse of, or the inability to use this information.