The flight was headed to Paris on Thursday but there was an issue with one of the engines.
VIDEO: Tire falls off United flight departing SFO, crushing several vehicles in parking lot, company says
Witness describes tire from United flight falling into SFO lot
United says the flight landed safely and everyone was able to safely get off the plane.
The flight was eventually cancelled and the airline says it's working on providing customers with flight options today.
This is the latest in a series of United Airlines flight issues, many out of SFO.
MORE: United plane apparently loses external panel mid-flight after taking off from SFO, officials say
Earlier this month, United CEO Scott Kirby addressed the issues, saying safety is "at the center of everything that we do."
"While they are all unrelated, I want you to know that these incidents have our attention and have sharpened our focus," Kirby said.
United has also said The Federal Aviation Administration will take a closer look at the airline's safety after the string of incidents.