More Explosions.

Up in the hills behind where we lived, just outside Vernon, was an area that had been used for many years to train the Army, before and during World War 2.  As a result, and despite more recent efforts to clean things up, there was a fair bit of military material still laying around.  Now I don't mean the Army left guns or supplies of any consequence, but shell fragments, practice rounds from artillery and mortars and other bit and pieces.  Additionally, the area had small lakes and ponds, rattlesnakes, and other hazards.
Consequently it was a magnet for my young brother-in-law and his friends to explore and play games of various sorts.  One of the larger ponds had an island in the middle, locally named Turtle Island.  Such a thing as an island presented the irresistible challenge to the lads to build a raft and visit it.  After much labour collecting raft makings and assembling something float-able, they paddled over to the island.  Now they never told me the how, my presumption being they were sneaking a cigarette, but in the warm, dry summer, they accidentally (or deliberately) set fire to the grass on the island.
A rapid escape to shore by raft ensued, as the flames grew to consume the small sanctuary they had just left.  They knew they were in trouble, even though the flames could not spread from the island, and started to hightail it homewards.  Before they got far, there was an almighty explosion, presumably from an unexploded ordinance, and Turtle Island was no more.  It had totally disappeared, never to be seen again!
I guess there was no harm done, but there sure could have been some dead or injured boys!