What could have caused plane to crash in 30 seconds?published at 23:23 British Summer Time 12 June

23:23 BST 12 June

What exactly happened will only be revealed by a detailed investigation, but the moments after take-off can be the most challenging in aviation.

It is almost impossible to definitively establish what caused the disaster based on videos of the plane's brief flight, but the BBC has spoken to aviation experts to find out what might have caused the crash. They speculated on a few potential causes:

Rare double engine failure: Footage showed the plane flying low and the plane was airborne for 30 seconds. "There would have been no time for [the pilot] to react if he lost both engines," one pilot tells us.

Bird strike: Another possibility raised by some experts in India is a bird strike. Experts and pilots familiar with Ahmedabad airport have told the BBC that it is "notorious for birds".

Plane flaps: Three experts who spoke to BBC Verify suggested that the disaster may have occurred as the aircraft's flaps were not extended during take-off - though other pilots and analysts have challenged this.

• BBC Verify has explored the theories relating to the crash

The BBC's Samira Hussain says family members and friends of a number of the passengers who were on board the crashed plane have gathered in Ahmedabad's hospital for DNA tests to help identify their loved ones.

As we reported earlier, officials say it could take some time to complete the process of identification as the force of the crash was so intense that many of the bodies are unrecognisable.

Zoya Mateen
Reporting from Ahmedabad

Warning: This post contains distressing details.

A police official who wanted to stay anonymous has told the BBC that all the bodies and their remains have been removed from the site of the crash.

“It took hours to make sense of the chaos. And it’s going to take many more hours to completely clear up the site,” he says.

The official adds that apart from “one or two lucky ones”, everyone’s dead.

“And it’s not just those on board,” he continues. “The building the plane crashed on, the hospital, was full of medical students. Many have died from our understanding.”

“It’s going to be a long night for all of us.”

It's night time now in India, where loved ones of those who lost their lives in Thursday's fatal crash wait to claim their bodies outside Ahmedabad's Civil Hospital.

Let's take a look at the latest:

• Air India have confirmed that there was one survivor, named as British national Vishwashkumar Ramesh, who is recovering in hospital
• The other 229 passengers and 12 crew members were killed in the crash, the airline says
• A rescue operation at the crash site in Ahmedabad has been completed, India's civil aviation ministry says

As a reminder, at least 50 injured medical students were taken to hospital earlier today after the plane crashed into a doctors' hostel in the western Indian city.

India’s Federation of All India Medical Association said five students were missing, but we are yet to hear a further update.

Indian officials say they have now completed their rescue operation at a vast plane crash site in Ahmedabad.

The operation continued well into the night - here are some of the latest photos showing the sheer devastation in the western Indian city.

Image source, Reuters

Image source, Reuters

Image source, Reuters

Image source, Reuters

Zoya Mateen
Reporting from Ahmedabad

It's coming up 02:00 (21:30 BST) here in Ahmedabad but the city is buzzing with activity.

Legions of police vans patrol the streets. A steady stream of disaster force officials pours in and out of the site of the crash, which is still being cleared.

A gaggle of journalists remain perched near the barricades erected around the spot where the crash took place - they are not being allowed to go any closer to the debris.

While the crowds have gone down, there are still civilians around, trying to help in way possible, from serving tea to policemen and helping clear the trash from the streets.

What’s most striking, however, is the smell of smoke and burnt metal that lingers in the air, hours on from the crash.

Helen Catt
Political correspondent

The BBC understands that Foreign Secretary David Lammy has chaired a meeting of the government's emergency committee, Cobra, in response to the Air India plane crash.

Ishadrita Lahiri, Seraj Ali, and Shaili Bhatt
Reporting from Ahmedabad

Image source, EPA

It's approaching 1:30 in India, but it does not seem so outside the post-mortem room at the Civil Hospital in Ahmedabad.

Families and friends of those who’ve lost their lives in the crash wait to claim their bodies, but identification has become a difficult task. Authorities are trying to use DNA sampling, but the process is taking time.

Outside the hospital, the BBC’s team meets T. Thanglingo Haokip, whose cousin, Singson, was cabin crew on Air India flight 171.

Speaking to the BBC, Haokip explains that he has been trying for hours to get some information about Singson but has been unsuccessful.

He says: “Her parents are worried. She only has a mother, her father passed away. Her brother has cancer. She was the only breadwinner in the family. Her family was wholly dependent on her."

There’s been a steady stream of bodies coming into the hospital for post-mortems after the crash.

“Ever since the bodies started coming in, we’ve been examining them. We are exhausted. We have lost track of time," a doctor in the hospital tells us.

More from the Air India statement, which confirms that the sole survivor is a British national.

"Our efforts now are focused entirely on the needs of all those affected, their families and loved ones," the company says.

It adds that it's "giving its full-co-operation to the authorities investigating this incident".

Air India has just issued a statement confirming that 241 people on board the plane have been killed.

The airline adds that the "sole survivor" is being treated in hospital.

DNA testing of the victims of the plane crash is currently under way, a press release from Indian Home Affairs Minister Amit Shah says.

Shah, who has now visited the crash site after earlier speaking to survivors in hospital, says that only once DNA testing is complete will an official death toll be released.

"On behalf of the government of India, the government of Gujarat, and the prime minister, I express deep condolences to all those who lost their lives," the statement reads.

The rescue operation at the crash site in Ahmedabad has been completed, India's civil aviation ministry says.

Image source, Getty Images

Warning: This post contains distressing details.

BBC correspondent Roxy Gagdekar has been speaking to people at the scene of the crash in Ahmedabad.

“We heard a loud noise. It sounded like a bomb blast,” one man says.

“There was smoke and fire. I said, ‘let's go and see’. Someone said that the plane had fallen,” he says, adding: “As soon as I got there, I saw that the plane was on fire. There were three people lying nearby.”

Another man, a taxi driver who was working nearby, says: “When I saw the smoke, I ran there. I couldn't go near the plane, there were dead bodies outside.”

“The plane’s wing had come out on the main road. There was smoke everywhere,” he says.

Sima Kotecha
Senior UK correspondent

At a Hindu temple in Harrow, Middlesex, 60 or so worshippers have congregated to pray for those killed and hurt in the crash.

The Metropolitan Police also has a presence here, with officers joining in with the musical prayers.

The priest told the congregation it was a “dark day” as more news came in of the death toll.

He emphasised this was not about one community but for all those who’ve been affected by what he called “a dreadful tragedy”.

The congregation chanted continuously for at least 20 minutes with some members closing their eyes in prayer.

The mood is solemn. But an elderly Indian woman told me prayer is providing much-needed comfort at this time.

Image source, EPA

The answer to what went wrong for Air India Flight 171 may lie in the plane's black boxes - small but sturdy electronic data recorders.

Planes generally carry one to record sound from the cockpit so that investigators can hear what the pilots are saying and listen out for any unusual sounds that may give them a lead. A second also records flight data, like altitude and speed.

Typically, black boxes are kept in the tail of the plane, thought to be the section that is typically least damaged in the event of a crash.

We're yet to hear whether the black boxes for Flight 171 have been recovered, but if they are, don't expect immediate answers - it can sometimes take days or weeks to analyse the data.

Image source, Reuters

Boeing President and CEO Kelly Ortberg has now issued a statement about the crash, saying his thoughts are with the victims.

"Our deepest condolences go out to the loved ones of the passengers and crew on board Air India Flight 171, as well as everyone affected in Ahmedabad," he says.

Ortberg says he spoke with Air India Chairman Natarajan Chandrasekaran "to offer our full support", and reiterates that Boeing will support an investigation led by India's Aircraft Accident Investigation Bureau.

Image source, Reuters

Here's a quick recap of what we know at this point about the Air India plane crash at Ahmedabad's airport:

• The London-bound Boeing 787-8 Dreamliner with 242 people on board crashes into a residential area just moments after take-off at about 13:38 local time (09:08 BST) on Thursday
• Dramatic footage later emerges showing the aircraft taking off before slowly coming down in a built-up area. Plumes of black smoke are then seen rising high into the sky after an explosion upon impact
• Local police say 204 bodies have since been recovered from the crash site - it's not known how many of those victims were on the plane, or were on the ground when the plane crashed
• Ahmedabad's police chief tells Indian media there is one survivor from the plane - he is reported to be a British national named Vishwashkumar Ramesh
• There were 169 Indian nationals, 53 Britons, seven Portuguese nationals and one Canadian on the flight
• At least 50 injured medical students are being treated in hospital after the plane crashed into a doctors' hostel in the western Indian city
• A search operation is continuing overnight at the massive crash site
• Teams of US and UK specialists are heading to India to assist with the investigation

Stay with us, as we'll continue bringing you all the latest developments as well as photos and videos - as soon as we get them.

Yogita Limaye
South Asia and Afghanistan Correspondent, reporting from Ahmedabad

What strikes you as soon as you enter the area where the crash happened is this kind of burning smell in the air, which grows stronger and stronger.

Where we are, there are still very acrid fumes. In front of me I can see the fire brigade, which is pointing a giant hose towards one of the buildings to put out the fire that is still burning, blazing inside.

There's a charred tree but I can see parts of it right at the top still smoking. I can see sparks from there and right next to me, there's also a fallen tree, which is also smoking.

Ever since I've walked in, I've just seen hundreds of rescue workers, scores and scores of police officers everywhere, ambulances.

This is a massive plane that crashed - a Dreamliner aircraft - but you've got to be on the ground to just see the scale of devastation.

The scale of the tragedy is just truly, truly, much more massive than perhaps what I had imagined when I got here.

All you can see is charred bits and pieces, metal bits, bits of concrete blocks, bricks, strewn all about.

I can see what appear to be parts of charred bits of the body of a plane, but I don't think anybody can be sure of what that was. This really just feels like an apocalyptic scene.

I'm not sure I've ever seen a scene of such devastation from one incident which looks like this before.

Image source, Yogita Limaye/BBC

Image source, PA Media

UK Prime Minister Keir Starmer says the news from India following today’s crash of a plane bound for London Gatwick in Ahmedabad is “absolutely devastating” and he “speaks for the entire country in saying our thoughts are with everyone involved”.

Speaking to broadcasters, he says a UK team had been dispatched to Gujarat to join the investigation, and urges families and friends of anyone affected to contact the Foreign Office.

“Our hearts and our thoughts are absolutely with the friends and families of everyone affected who’ll be absolutely devastated by this awful news”, he says.

Indian Home Affairs Minister Amit Shah has met people injured in the crash - including the man who seems to be the only survivor from the plane itself, British man Vishwashkumar Ramesh.

Footage from news agencies showed Shah meeting Ramesh in his hospital bed. Ramesh earlier spoke to reporters from hospital, while the BBC interviewed one of his relatives in Leicester.

Image source, Reuters