Investigators examining the disappearance of Malaysia Airlines Flight 370 more than four years ago completed their inquiry on Monday without definitive conclusions on the cause. The flight, carrying 239 people from Kuala Lumpur, Malaysia, to Beijing on March 8, 2014, vanished after having inexplicably veered off course.

The unsolved mystery has added Flight 370 to aviation history’s most vexing disappearances and unexplained crashes. Here are some others:

Amelia Earhart



Amelia Earhart vanished during her attempt to become the first woman to pilot a plane around the world in the late 1930s, a case that continues to fascinate.

Ms. Earhart and her navigator, Fred Noonan, took off from Lae, New Guinea, in a Lockheed Electra on July 2, 1937, bound for Howland Island about 1,900 miles southwest of Honolulu. A news agency report suggested their fuel had run low. More than 80 years later, the pair’s fate remains unknown.