The masks provide oxygen to passengers in emergencies up to 40,000 feet, according to the Federal Aviation Administration. When cabin pressure drops in a plane, passengers need the masks in order to receive a sufficient flow of oxygen.
The masks prevent hypoxia, when the body lacks enough oxygen to maintain normal physiological function. A mask will work for a short time, during which the pilot must get the plane to a safe altitude where it is no longer needed.
One woman was killed after the plane en route from New York to Dallas blew an engine and made an emergency landing in Philadelphia, Southwest said on Tuesday. It marked the first fatal U.S. commercial plane accident since 2009.
The victim was Jennifer Riordan, a New Mexico resident and mother of two, who served as vice president for community relations at Wells Fargo in Albuquerque, according to her LinkedIn profile. She managed employee volunteer service to nonprofit groups.