LOS ANGELES, July 9 — United Airlines said it is investigating how the wheel of a Boeing 757-200 fell off on takeoff from the Los Angeles International Airport yesterday.

SAN FRANCISCO, Feb.

WASHINGTON, Jan 9 — United Airlines said Monday it has found several instances of loose bolts holding down exit plugs on its fleet of Boeing 737 Max-9 aircraft similar to the one that blew off during an Alaska Airlines flight.

CHICAGO/WASHINGTON, Oct 1 — American Airlines and United Airlines, two of the largest US carriers, said they were beginning furloughs of over 32,000 workers on Thursday as hopes faded for a last-minute bailout from Washington.