Aircraft engines, for obvious reasons, are supposed to be reliable, but having one tank is a recurring nightmare for many pilots. How often does it happen? Often enough, but as AVweb's Paul Bertorelli reveals in this video, the risk is not really as high as many of us imagine and more than half of engine failures are caused by pilot or mechanic mistakes.
Here's a video on how water contamination caused one deadly crash. It relates to material in this video. https://www.youtube.com/watch?v=KI1QKEsxw8k&t=562s
How about the runway turnback maneuver. That topic is covered in this video: https://www.youtube.com/watch?v=byBh1Qd6IgA&t=15s
Landing on a beach is occasionally an option after an engine failure. Here's what's involved: https://www.youtube.com/watch?v=0LwGYBBhTss&t=1s
And, of course, you can always land on a road or highway: https://www.youtube.com/watch?v=99DomTe9JY4&t=348s