NEW DEHI (AP) -- Authorities began investigating one of India's worst aviation disasters after an Air India plane crashed a day earlier that killed all but one of the 242 passengers and crew onboard, officials said Friday, as Prime Minister Narendra Modi visited the crash site.

The Indian government has launched an investigation into the fatal crash of the London-bound Air India plane that came down in a in a residential area in the northwestern city of Ahmedabad minutes after takeoff on Thursday.

Officials said most of the bodies were charred beyond recognition.

Civil Aviation Minister Ram Mohan Naidu in a statement on the social media said the Aircraft Accident Investigation Bureau has initiated the probe in line with global protocols set by the International Civil Aviation Organization.

A team from the U.S. is expected in India to help with the probe. The National Transportation Safety Board, Federal Aviation Administration, Boeing and General Electric are all sending experts.

There was no update on retrieving the black boxes, the flight data and cockpit voice recorders, as authorities continued searching the crash site.

Akshay Dongardiv, national president of the Federation of All India Medical Association, said medics had begun conducting DNA tests as grieving families gathered outside the Civil hospital in Ahmedabad on Friday.

The plane hit a building hosting a medical college hostel and burst into flames, killing several college students on the ground. Black smoke billowed from the site where the plane crashed near the airport in Ahmedabad, a city of more than 5 million and the capital of Gujarat, Prime Minister Narendra Modi's home state.

Modi visited the crash site and the local government hospital where the injured are being treated. He is scheduled to hold a meeting with senior officials later in the day.

Indian Home Minister Amit Shah confirmed that he met the sole survivor at the hospital. A doctor said he had examined the survivor, whom he identified as Vishwashkumar Ramesh.

"He was disoriented with multiple injuries all over his body," Dr. Dhaval Gameti told The Associated Press. "But he seems to be out of danger."

Another medic said Ramesh told him that immediately after the plane took off, it began descending and suddenly split in two, throwing him out before a loud explosion.

Thursday's Air India crash involved a 12-year-old Boeing 787. The cause of the crash remains unclear. Boeing planes have been plagued by safety issues on other types of aircraft.

According to experts, there are currently around 1,200 of the 787 Dreamliner aircraft worldwide, and this was the first deadly crash in 16 years of operation.