Westworld: 31 WTF Moments From Season 1
23. Robo-Suicide
Pretty self-explanatory, this one.
Elsie and Ashley are out investigating a lost host, and when they come across him he emerges carrying a huge boulder.
At first it looks like he might attempt to hit one of them with it, but ultimately brings it down on his own head, in the first case of robo-suicide on Westworld. And, of course, it's absolutely brutal and gory to watch.