This U.S. squadron went back into battle with no ammunition

It's Memorial Day weekend in 1911, and an American institution is about to emerge, engines roaring and tires screeching, to capture the imagination of the public. It's the very first Indy 500.

The first Indy 500 had its share of thrills and spills (1:51)

After two years of incubation, a swarm of mayflies rise from the bottom of the Mississippi River, like a biblical plague. They'll live for just one day.

This swarm of mayflies is big enough to fool weather satellites (3:09)

"Houston, we've had a problem": Those words, uttered by Apollo 13 astronaut Jack Swigert on April 13, 1970, were a prelude to one of the most thrilling rescue operations in human history.

A deadly leak on Apollo 13 endangers the entire mission (4:16)

A thorough examination of the wreckage of TransAsia Airways Flight 235 has so far failed to yield any clues about its February 4, 2015 crash. If NTSB investigators are going to arrive at answers, they'll need to expand their thinking.

Crossing off reasons why TransAsia Airways Flight 235 crashed (3:14)

Until January 30, 1968, the Vietnamese New Year had always brought an informal ceasefire. But this year, the cessation of hostilities would vanish in a deadly attack on the U.S. Embassy in Saigon.

The New Year's attack that turned the tide of the Vietnam War (2:48)

A solider stationed in Iraq set out to find a solution to the deadly ambushes that were plaguing U.S. convoy trucks. His journey led him to a Vietnam vet, who became a mentor and a friend.

A U.S. soldier in Iraq turns to a Vietnam vet for answers (3:56)

It's September 26, 1997 and Garuda Indonesia Flight 152 has just been instructed by air traffic control to turn right onto a vacant runway. Inexplicably, the captain ignores these instructions—with disastrous consequences.

An incorrect turn ends in a deadly disaster (3:45)

Thrust reversers are only supposed to deploy when a plane is landing. Did one of the thrust reversers on US Air Flight 1016 activate prematurely? And did that contribute to the crash on July 2, 1994?

Did a faulty thrust reverser bring down Flight 1016? (2:49)

Even before everything started to go wrong, many thought that with the mission number 13 and the launch time 13:13, Apollo 13 was tempting fate.

The superstitions surrounding Apollo 13 (1:52)