A plane appeared to bounce after landing at the Caribbean Island airport of Sint Maarten and skidding down the runway.
Authorities said one passenger was treated for burns after a seat caught fire from the burning phone. Another was reportedly injured during the evacuation.
Chaotic video from one of the passengers shows a chaotic scene as people went down the slide.
"While they are all unrelated, I want you to know that these incidents have our attention and have sharpened our focus," United CEO Scott Kirby said.
Passengers were evacuated from a United flight at Houston's George Bush Intercontinental Airport, according to an airport spokesperson.
Some passengers who experienced the ordeal aren't happy with how the airline has handled it, and have since hired lawyers, including Joanie and Gilbert Marin of Riverside.