But the day after American Airlines Flight 5342 collided with a U.S. Army helicopter in Washington, D.C., killing all 67 people onboard, shares of the company were trading just 2.5% lower. The decline grew four days later,

While landing at Ronald Reagan Washington National Airport in Washington, D.C., on Wednesday shortly before 9 p.m., American Airlines Flight 5342 collided with an Army Black Hawk helicopter and crashed into the icy Potomac River.