Welcome to the News Hour. Investigators are trying to determine what led to one of the worst airline accidents in decades.

More than 240 people died today after a London-bound Air India flight crashed just moments after takeoff.

All but one of the 242 people on board reportedly perished. And authorities are trying to determine how many other people

were killed on the ground when the plane crashed into a building in the city of Aminabad in western India.

As John Yang reports, it was the first fatal accident with a Boeing 787 Dreamliner. A warning,

this report contains graphic video. It all happened in less than a minute.

Air India Flight 171 took off at 139 p.m. local time bound for London.

On board, 242 passengers and crew.

It climbed to just 625 feet and then started sinking.

Within moments, the Boeing 787 Dreamliner crashed just outside the airport perimeter, hitting a hostel for medical students.

Videos from the site show the plane's tail jutting out from the building.

My daughter's father-in-law, his name is Vardyshan, was on the flight.

I dropped him to the airport and came home when we got the message that the plane had crashed.

Another video shows the plane's slow descent, as if it was landing.

Indian officials said the pilot issued a Mayday call, the international distress signal,

but the flight crew didn't respond to subsequent calls from air traffic controllers.

Within seconds, a fireball and thick black smoke.

Air India CEO Campbell Wilson.

I know that there are many questions, and at this stage, I will not be able to answer all of them.

The investigations will take time, but anything we can do now, we are doing.

Miraculously, passenger Ramish Wishfush Kumar walked out alive, the sole survivor.

He was assigned seat 11A next to one of the main exit doors. It said he jumped off the plane. Of the 241 others on board

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