flightaware.com/live/flight/UAL8 … /KSFO/KORD
I’ve got the story on this one - my dad was the captain on the flight. A woman had a pulmonary embolism (blood clot in the lung) enroute and they diverted to KSLC. Not sure why the route looks so messed up on Flight Aware, but they turned around over southwestern Wyoming, landed and then continued on to KORD.