What we know so far after Air India flight to London crashes in Ahmedabad
ReutersAn Air India enger plane bound for London's Gatwick airport crashed shortly after taking off in Ahmedabad, western India, on Thursday, killing 241 engers and crew.
At least eight local people on the ground, including four medical students, were also killed, a senior health official told the BBC.
It later emerged that only one enger on the plane, a British man, had survived.
Among those on board were Indian, British, Portuguese and Canadian nationals. Details are still emerging from the scene.
When and where did the plane crash?
Air India flight AI171 left Ahmedabad's Sardar Vallabhbhai Patel International Airport at 13:39 local time (08:09 GMT), Air India said.
It was scheduled to land at London Gatwick at 18:25 BST.
Moments after departing Ahmedabad, the plane lost altitude and crashed into a residential area of the city called Meghani Nagar.
ReutersAccording to flight tracking website FlightRadar24, the signal from the aircraft was lost "less than a minute after take-off".
Flight tracking data ends with the plane at an altitude of 625ft (190m).
The plane gave a mayday call to air traffic control, India's aviation regulator said. No response was given by the aircraft after that.
Doctors' hostel struck
The plane crashed into a building that was used as doctors' accommodation at the Byramjee Jeejeebhoy Medical College and Civil Hospital.
It was lunch break at the hostel when parts of the plane crashed through the roof of the dining hall.
A photograph taken after the crash showed abandoned tables and plates of food in the hostel's canteen. At the far end of the room, people gathered to inspect a huge hole in the wall, apparently caused by the impact of the plane.
One woman at the scene said that her son jumped from the second floor of the hostel, sustaining injuries, when the plane crashed.
Dr Minakshi Parikh, the dean of the BJ Medical College and Civil Hospital, told the BBC that at least four students and four doctors' relatives had died.
On Friday, staff at the hospital were busily trying to identify bodies as hundreds of relatives waited anxiously for news.
"We are relying on DNA matching to identify them," Dr Parikh said. "It is something where we simply cannot rush or afford mistakes."
Family have been asked to submit DNA samples to the hospital so that doctors can check if there are matches with the bodies that have been found.
Authorities have said they will release an official death toll once all DNA testing has been completed.
Verified footage taken in central Ahmedabad showed huge plumes of black smoke in the sky.
The BBC's Roxy Gagdekar said people near the scene were running to "save as many lives as possible".
He said emergency services were involved in a rescue operation and trying to extinguish a fire, and described seeing bodies being taken from the area.
Warning: the following clip contains distressing footage.
Who was on board?
Air India confirmed that there were 242 engers and crew on board the Boeing 787-8 Dreamliner, which has a total of 256 seats.
There were 169 Indians, 53 Britons, seven Portuguese nationals, one Canadian and 12 crew on the plane.
The sole survivor of the crash was Vishwashkumar Ramesh, a British man who was sitting in seat 11A.
India's state broadcaster DD News has spoken to Mr Ramesh, who is currently being treated in hospital.
"I still cannot believe how I made it out alive," he said.
"At first, I thought I was going to die. I managed to open my eyes, unfastened my seat belt and tried to exit the plane."
Mr Ramesh said the side of the plane that he was sitting on did not hit the hostel and was closer to the ground floor. "My door broke down and I saw a small space," he said. "I tried to get out of the plane."
He said he did not know the whereabouts of his brother, Ajay, who was also on the plane.
The Foreign Office has been in with Mr Ramesh "to offer consular ", Downing Street said.
A family from Gloucester - Akeel Nanabawa, his wife Hannaa Vorajee and their daughter Sara - are among those who were on the flight. In a statement, Gloucester Muslim Society said it was "profoundly heartbroken" and offered its "deepest condolences" to the family.
Ammaarah Taju, the granddaughter of a couple on the plane, told the BBC from her parents' home in Blackburn that the family is "clinging onto hope" they are still alive.
Adam Taju, 72 and his 70-year-old wife Hasina were flying with their son-in-law Altafhusen Patel, 51, who lives in London with his wife.
An "emergency centre has been activated" and a team put in place for families seeking information, Air India's chairman Natarajan Chandrasekaran said.
The Foreign Office said British nationals with concerns about friends or family should call 0207 008 5000. As of Friday morning, Downing Street said the helpline had received "almost 300" calls.
What do we know about the plane?
The aircraft involved was a Boeing 787-8 Dreamliner.
The model was launched 14 years ago. Just six weeks ago, Boeing lauded the fact that it had reached the milestone of carrying one billion engers.
Air India operates a fleet of more than 190 planes including 58 Boeing aircraft, according to its website.
The crashed 787 Dreamliner was 11 years old and had completed more than 700 flights in the year leading up to the disaster, Flightradar24 data showed.
In a statement, Boeing said: "We are in with Air India regarding Flight 171 and stand ready to them. Our thoughts are with the engers, crew, first responders and all affected."
India's aviation regulator has ordered safety checks on the airline's entire Boeing-787 fleet.
The Directorate General of Civil Aviation has also announced that from 15 June one-time checks of take-off parameters will be implemented for every departure of a Boeing 787-7 or 787-9 plane. Power assurance checks will begin in two weeks.
Did wing flaps play a role in causing crash?
Aviation experts have told the BBC the position of the plane's wing flaps as it took off may have caused a problem for the plane.
One video verified by the BBC shows the plane descending before a large explosion occurs as it hits the ground.
"When I'm looking at this, the undercarriage is still down but the flaps have been retracted," aviation analyst Geoffrey Thomas said.
Another expert, Terry Tozer, said: "It's very hard to say from the video for sure, it doesn't look as if the flaps are extended and that would be a perfectly obvious explanation for an aircraft not completing its take-off correctly."
"That would point to potential human error if flaps aren't set correctly," said Marco Chan, a former pilot and a senior lecturer at Buckinghamshire New University. "But the resolution of the video is too low to confirm that."
What have the airline and authorities said?
After confirming that the London-bound flight on Thursday morning had been "involved in an accident today after take-off", Air India said that it was fully co-operating with authorities investigating the crash.
The airline has set up a dedicated enger hotline to provide further information: 1800 5691 444.
A spokesperson for Sardar Vallabhbhai Patel International Airport said all operations had been suspended until further notice. They advised engers to check with their airline before travelling to the airport.
Tata Group, which owns Air India, has said it will give 1 crore rupees - the equivalent of around £86,000 – to the families of each person killed in the crash. It also said that it would cover the hospital bills of those injured and help to rebuild the medical college hostel.
The chief executive of Air India, Campbell Wilson, described his "deep sorrow" following the incident.
"This is a difficult day for all of us at Air India and our efforts now are focused entirely on the needs of our engers, crew , their families and loved ones," he said in a video statement.
APA formal investigation has been launched by India's Aircraft Accident Investigation Bureau (AAIB) into the cause of the crash. A team of US investigators led by the National Transportation Safety Board (NTSB) will travel to India to lend .
Air India and Boeing have said they will cooperate with the investigation.
On Friday, India's civil aviation minister said one of the plane's two black boxes - or flight data recorders - had been retrieved from the crash site in Ahmedabad.
"This marks an important step forward in the investigation," Ram Mohan Naidu Kinjarapu said. "This will significantly aid the inquiry into the incident."
How have India and the UK reacted?
India's Prime Minister Narendra Modi visited the site of the crash in his home state of Gujarat on Friday, and later said "the scene of the devastation is saddening" in a post on X.
Modi also visited Ahmedabad's Civil Hospital to meet some of those injured in the disaster, including the sole plane survivor Vishwashkumar Ramesh.
UK Prime Minster Sir Keir Starmer said the scenes from Ahmedabad were "absolutely devastating".
Foreign Secretary David Lammy said the UK was working with local authorities in India to "urgently establish the facts" and provide .
A team of UK experts has also been deployed to India to assist with the formal investigation.
King Charles and Queen Camilla said they were "desperately shocked by the terrible events in Ahmedabad" and extended their sympathy to those affected.
The King said in a statement: "I would like to pay a particular tribute to the heroic efforts of the emergency services and all those providing help and at this most heartbreaking and traumatic time."