I remember tripping over carbon monoxide alarms. Someone in the house had carelessly left it on the floor right near the staircase. I later found out it was my husband who was reluctant to own up as he thought I was going to shout at him. I heard the phone ring and ran down the stairs and all of a sudden I was on the floor. I was in agony. I happened to glance over and saw the dector on the ground. Fortunately I did not break anything and have recovered. I have told my husband to always keep it in the closet where it belongs.