Last week was a tough week for United Airlines, which experienced four separate incidents aboard its flights, including an emergency landing, lost tire, engine fire, and runway roll-off. No injuries were reported as a result of any of the incidents.

On Friday, a United jetliner with 110 people aboard and headed to Mexico City from San Francisco made an emergency landing in Los Angeles after the crew reported a hydraulics issue. The Airbus 320 landed safely at Los Angeles International Airport.

The emergency landing at LAX came hours after passengers had to be evacuated from an United Airlines Boeing 737 Max flight with 160 passengers after the plane rolled off a runway and got stuck in the grass in Houston, Texas.

Meanwhile on Thursday, another United Airlines flight made an emergency landing in Los Angeles. The Boeing 777-200 jetliner bound for Japan lost a tire while taking off from San Francisco.

Video footage showed the plane losing one of the six tires on its left-side main landing gear assembly only seconds after takeoff. The tire landed in an employee parking lot at San Francisco International Airport, where it smashed into a car and shattered the back window before breaking through a fence and coming to stop in a neighbouring lot.

And earlier in the week, a United flight from Houston to Fort Myers, Texas, was forced to turn around Monday after one of the plane’s engines caught fire. Several of the 167 passengers aboard the Boeing 737 took videos showing a line of flames shooting out of the engine.

Boeing shares fell as much as 1.4% after the United incident on Friday. The stock declined 0.8% as of 12:06 p.m. in New York, continuing the worst drop this year among members of the Dow Jones Industrial Average. United slipped 0.5%.