it has happened from time to time
In Sheffield, late 70s, some kids were pratting about on the lifts at Hyde Park Flats (I think, it could have been Park Hill, but I think it was Hyde Park) One was decapitated as the lift went up.

Similarly, at the end of the 70s also, a small child (a girl of about 8) was killed after a 15 year old (not the full ticket) lobbed a telly off one of the upper balconies (the flats were 18 stories tall at the highest point).

Both urban legends, but both happened (perhaps causing the legends). Any Sheffielders in their 30s can verify this.
( disasterprone "Pyjamas caused the Holocaust", Fri 4 Mar 2011, 7:31, 2 replies)

I am fairly sure...
That also there was a recent case in Japan of a doctor doing something similar... I cant be certain though, actually this being the interweb I can, it was in the USA www.houstonpress.com/2003-10-09/news/catching-elevators/
(Bonzodog29 is an unemployed sponge of the worst kind, Fri 4 Mar 2011, 9:55, closed)

Anecdotally,
A building site in Glasgow next to the one I was working on had a young lad steel erecting (fnar) in a cherry picker, was driving it with the boom raised and extended and didn't spot the raised manhole cover he was driving over until it catapulted him head first into a rafter, crushing his skull.
Later turned out he'd had next to no training on the machine (shown which lever does what and 'off you go') and didn't have a cscs card (which most sites now insist on you having, since it shows you're not a complete numpty, and can pass a multiple choice exam), so health and safety were all over that estate for the next few months making everybodies jobs harder.
The next day we were back at work, a young ned was seen in the car park, trying to sell a slightly used pair of work boots and high visibility jacket...
(Hairy Bob, Sat 5 Mar 2011, 17:26, closed)