Last night I just nipped back out to my car because I had forgotten something. As I closed the front door behind me, an icicle at least 18 inches long from the guttering overhead dislodged and damn near parted whats left of my hair.
The point to this is be carefull going through doorways, and take the time to just look up and check for any icy swords of damocles before you do!
at the wrong time. I recall an accident that occurred in a local nuclear power station basement when the man heard a 'rattle' above him, looked up, and had an eye pierced by a piece of welding rod. Chances are, if he had ducked, he would have been OK.
My advice re WTM's icicles would be to step smartly through the doorway and then look back out of curiosity.