President Xi Jinping expressed his great sorrow and sent his condolences to the victims on Sunday.

The two Chinese teenagers who died — Ye Mengyuan, 16, and Wang Linjia, 17 — had been sitting in the rear section of the aircraft.

Wang Linjia's parents were devastated after hearing the news of their daughter's death. Ge Yuejin / for China Daily

San Mateo County Coroner Robert Foucrault told a local newspaper that one of the two girls appeared to have been thrown from the rear of the plane and landed on the runway when the tail broke off. The second girl was found outside the aircraft near the left wing, according to Foucrault.

The flight, which originated in Shanghai on Saturday, first flew to Seoul to take on more passengers before departing later than scheduled at 5:04 pm Korean time. It arrived in San Francisco at 11:28 am local time.

US federal authorities are looking into reports that the plane may have hit the sea wall on an approach area that juts out into the harbor, the Los Angeles Times reported.

A Chinese pilot surnamed Wang, who witnessed the accident from a boarding gate, told China News Service that he saw the plane's wheels and tail hit the sea wall before the crash.

Most of the passengers evacuated via inflatable emergency slides and left the plane as plumes of smoke started to rise.

Worried parents gathered at Jiangshan High School on Sunday. They were briefed about the latest developments and school authorities helped them contact the Chinese consulate in San Francisco and Zhejiang's foreign affairs department to make sure assistance was delivered to the children.

A Jiangshan official who was visiting the US rushed to San Francisco to provide assistance, according to the Jiangshan government.

Officials from the Chinese consulate visited eight of the injured Chinese passengers at San Francisco General Hospital. Most of the injuries were slight. A 4-year-old boy, who was traveling with his mother and cousin, broke some bones in the crash, according to Wang Chuan, a consulate press officer.

An injured survivor is transferred to San Francisco General Hospital. Chen gang / Xinhua

Passenger Xu Ruonan sent her mother a text message on Saturday. The 16-year-old said she had arrived safely in San Francisco, but didn't mention that she had survived an air crash.

Chen Aiwu, her mother, said on Sunday that she learned about the crash from the television news and quickly contacted her daughter, who was part of a group of 30 students and six teachers from Jiangshan High School in Quzhou, Zhejiang province.

"She told me she was seated in the middle of the aircraft and passengers were evacuated in an orderly fashion," said Chen, who was relieved to discover that her daughter's injuries were slight, mainly minor bruising, and that she was helping to take care of injured classmates at a hospital.

"She said her mobile phone had run out of power, as had those of many of her schoolmates, but their chargers were burned along with their other belongings in the luggage hold," she said.

Chen said she was relieved to hear that her daughter was safe and urged her to take care of herself and comply with the teachers' requests.

"She sounded very calm on the phone," she said. "My girl travels a lot and she doesn't panic in emergencies."

A couple embrace as they watch a news conference with airport and city officials at San Francisco International Airport. Justin Sullivan / Getty Images / AFP