It all happened a few years ago. Thoughts from the artist:
"I was out on an research expedition to drop an unmanned submarine drone into a extremely deep oceanic trench. The vessel fell slowly, approaching the bottom at a crawl, with pressure building along the way. The strain of the pressure on the vessel grew steadily until it finally overloaded the sensors and components sending the signals back up, stranding the vessel forever. There was a peaceful moment in which I felt the vessel continue its path, surrounded by a pale light and total blackness, until it all faded into nothing."