You're listening to the Global News podcast from the BBC World Service.

Hello, I'm Oliver Conway. This edition is published in the early hours of Saturday, the 12th of July.

A report into the air India crash last month says the fuel supply was switched off just after takeoff.

On a visit to Texas with the First Lady, President Trump dismisses a question about the effectiveness of flood warnings.

And Palestinian officials tell the BBC that Gaza ceasefire negotiations are on the verge of collapse.

Also in this podcast, this is extremely significant.

It's the first time that we have a clear picture of what timely access to vaccines through a stockpile in an outbreak situation can really do.

A new study finds that emergency vaccinations have saved hundreds of thousands of lives.

One month ago, Air India Flight 171 plunged into a building seconds after taking off from Ahmedabad Airport.

260 people died, including all but one person on board.

An initial report released in India in the early hours of Saturday says both fuel control switches in the cockpit were moved to the cutoff position just after takeoff. This caused both

engines to lose thrust. In the voice recording, one of the pilots is heard asking the other

why he did the cutoff. The other pilot responded that he didn't. So what does it all mean?

David Gleave is an aviation safety investigator. I'm not ruling out the possibility of some software

issue or an electrical arcing problem or something like that, causing the signals to the relevant computers from sending

that type of signal. The one second time gap is typically associated with how frequently the switch

positions are sampled. So it could have been almost instantaneous. It could have been within

almost next to each other or within two seconds,

depending on where within the one second sampling time they were switched. Or it could be some

form of human deliberate act. At the moment, a lot of analysis will go in to say how could this

have happened electrically or electronically, as well as human intervention?

We do have the finding, though, relating to the voice box recording where one pilot asks the

...