Fort Worth-based American Airlines has the second-largest fleet among major U.S. carriers. The airline, which operates its central hub at DFW

As everyone on board was loaded off the plane, four flight attendants and one passenger were rushed to a nearby hospital as a precaution, according to American Airlines.

Around 6,000 planes have been grounded to undergo an urgent software update after a vulnerability was identified.

American Airlines was among the carriers addressing the order. It’s begun identifying and completing the software update and expects the work on the vast majority of its A320 planes to be completed Friday and Saturday. The fix should take about two hours for many aircraft, American said.