My family went on a hike to the Paradise Ice Caves (Mt Rainier NP) when I was 12. I was totally hooked, but I wished that I could have been there without parental supervision so I could have done some off-trail exploration.
I only had to wait a month or so for my wish to come true. (Be careful what you wish for...) I was invited to join my older brother's Boy Scout troop for a repeat of the same hike to the ice caves. There was adult supervision, but it was kind of lax. I guess we were old enough to be expected to act responsibly and with a bit of common sense. Oops. While the scout masters and most of the rest of the scouts were exploring the inside of the caves, I was outside with a couple of other miscreants studying the Paradise Glacier which rose up above us- presumably all the way to the summit. It seemed so close! What the hell! We ducked under the rope barrier, ignoring the warning signs and began to hike up the glacier in tennis shoes, shorts and t-shirts. The number of climbing rules we were breaking could probably fill a book almost as thick as "Mountaineering: The Freedom of the Hills".
We got only a very short distance when there came a loud squeaking noise from just up ahead. Then a loud crash and a cloud of white spray burst up from a section of the glacier just beyond view on the slope we were climbing. Something big had just collapsed and it certainly got our attention. We wasted no time in retreating back to the 'safe' side of the rope barrier. Lucky for us, The Mountain was in a generous and benevolent mood that day when it spared the lives of a bunch of young 'mountaineers'. (I was still hooked for life, though. )