I'm playing RollerCoaster Tycoon Deluxe and I already observed it twice that a mechanic drowned in the lake. It happened in two different parks, in both cases there was a path and a rollercoaster station along the coast. I couldn't tell where exactly the mechanics drowned since I only got alerted by a red notification "mechanic # has drowned!" when they already were gone.
How and why does that happen?