A few years ago, I lived in a maisonette, one of 8 above a row of shops, my front door opened on to a flat roof at the rear of them
All our heating and cooking was propane, as most of us who lived there worked the local dealer would leave bottles while we were out and collect the empties.
This all had to stop as the local yobs used to think it great fun to turn on the valve and light the bottles sending them flying across the roof at what seamed to be 100 miles per hour, mine was at one end of the roof with a small wall at the side which was the raised roof of the newsagents downstairs. Eventually they put a hole through the wall with a bottle sending it crashing into the shop below
Dangerous things and very unpredictable