Flight 191 leaves Chicago on May 25, 1979, and crashes into a trailer park 31 seconds after take-off, claiming the lives of 273 people.

Investigation into the cause of a tragic accident that claimed the lives of 109 passengers and crew.

A plane crashes into a residential area of New York City two months after the Sept. 11, 2001, terrorist attacks.

In 1995, the Soufriere Hills volcano in Montserrat erupted for the first time in recorded history leaving many villages burned and 19 people dead.

Statistically, traveling by airplane is safer than driving and other forms of transportation, but when something goes wrong during a flight, it can be catastrophic with potentially hundreds of lives at stake. This series examines some of the world's worst air disasters, using official reports, transcripts and interviews with people involved to tell the stories of midair mishaps and discover what went wrong in each case. Episodes include a discussion of how the weather affects flights -- including stories of aviation disasters and near-misses -- and a New Year's Eve flight that fell from the sky into the Florida Everglades.

Catastrophic incidents in aviation history are meticulously re-enacted, providing insight into what went wrong and if the crashes and near-disasters could have been prevented. Accounts from survivors combine with computer images to weave these gripping tales, and expert testimony reveals the hows and whys behind these events, some of which have resulted in important changes to aviation safety and regulations.

"Naked Science" strips away the layers of a scientific investigation into one of the big mysteries of our time, revealing through expert analysis realistic scenarios that either confirm or deny long-held assumptions and misconceptions.

This award-winning series presents compelling untold stories and covers a wide array of provocative subjects. "Explorer" aired for 25 years -- the longest-running documentary series in cable TV history -- before being relaunched in 2015 after a five-year hiatus. Each monthly episode of the new "Explorer" takes a similar deep dive inside a story from the pages of a recent National Geographic magazine issue, taking viewers not only to the most remote corners of the globe but also to the furthest reaches of the mind and deepest crevices of history -- on urgent missions of discovery.

Rituals and customs accepted in one culture may be thought of as downright bizarre in another. "Taboo" delves into that dichotomy, taking viewers across cultural borders to explore traditional beliefs and deliberate lifestyle choices, ranging from body modification and gender decisions to nudity and spiritual quests that test the limits of the human body.

How did we get here? How did humankind evolve from apes swinging in trees to astronauts walking on the moon? National Geographic's eight-part time-travel adventure series delves deep into history to highlight pivotal "origin" moments that fundamentally and irrevocably created modern living. Host Jason Silva ("Brain Games") guides viewers through a dazzling audio-visual portal to explore these events, such as the discoveries and applications of fire, medicine, money and transportation, while experts across each field inject commentary. The series also incorporates scripted storytelling and documentary sequences.

From the award-winning team of filmmaker Darren Aronofsky ("Black Swan") and producer Jane Root ("America the Story of Us"), this 10-part cinematic event series explores the fragility and wonder of planet Earth -- one of the most peculiar, unique places in the universe. Host Will Smith guides viewers on an unprecedented exploration, bolstered by an elite group of eight astronauts who provide unique perspectives and relate personal memoirs of the planet seen from a distance. Hourlong episodes delve into monumental events such as genesis, cosmic violence, human intelligence and alien life, oxygen, and survival vs. destruction.