The National Transportation Safety Board is set to meet again with the four pilots of the Asiana Airlines jet that crash-landed at San Francisco Intentional Airport Saturday.
Why the crash occurred and who or what is to blame are now the focuses of the safety investigation. Federal investigators have yet to indicate whether the crash can be attributed to pilot error, while they continue to analyze data recovered from the plane's black boxes.
Investigators have said Flight 214 was flying "significantly below" its target speed during approach when the crew tried to abort the landing just before the plane smashed onto the runway.
The investigation into the cause of the crash has noted that the pilot in charge of the flight was in his ninth training flight on the Boeing 777 and was 11 flights short of the worldwide standard to get licensed, according to company officials.
Pilot Lee Kang-kook had 43 hours of flight experience on the Boeing 777 and Saturday was his first time landing at the airport with that kind of aircraft, Asiana Airlines spokeswoman Lee Hyo-min said Monday at a news conference in Seoul, South Korea.
As authorities continue to investigate the Asiana flight, a Japan Airlines Boeing 777 en route to San Francisco early this morning had to return to Tokyo's Haneda airport after a warning flashed in the cockpit saying the jet's hydraulic fluid level was low, according to the airliner.
The plane, carrying 226 passengers, returned without incident.
Meanwhile, the parents of the two Chinese teens killed in Saturday's crash arrived overnight at San Francisco International Airport. An investigation is underway to determine whether one of the two dead girls might have been hit by a rescue vehicle in the immediate chaos after the plane crash-landed.
NTSB Chairman Deborah Hersman said investigators watched airport surveillance video Monday to determine whether an emergency vehicle hit one of the students. But they have not reached any firm conclusions. A coroner said he would need at least two weeks to rule in the matter.
"We really need to work and talk with people, conduct additional interviews and let the coroner do their work," Hersman said.
The two fatalities were identified as Wang Linjia and Ye Mengyuan, both 16 and students from China. The students had been in the rear of the aircraft, where many of the most seriously injured passengers were seated, Hersman said.
Thirty-seven patients remain hospitalized at San Francisco area hospitals with eight still in critical condition. More than 60 victims were treated at San Francisco General Hospital. Dr. Andre Campbell said he treated a number of the patients, two of whom were paralyzed by the crash.
"People have injuries to their chest, injuries to their spine, also abdominal injuries which were from the blunt-force trauma," he said.
Asiana Airlines Flight 214 was carrying 291 passengers and 16 crew members when it crashed. The tail was torn off as it crashed, and it burst into flames. More than 180 people were initially taken to local hospitals for treatment.
Three days after the crash, stories of heroism and chaos have continued to come from passengers and first responders.
When the Boeing 777 crashed, emergency chutes at two of the exits opened inside the aircraft. Passenger Eugene Rah says one of the flight attendants was pinned under the chute and all he could see was her leg.
"She was stuck in between," Rah said. "Or she was sitting, maybe the door had opened or something. And she was trying to give a signal to us by moving her leg."
Rah praised cabin manager Lee Yoon-hye, who helped maintain order and evacuate passengers.
"She was so tiny and skinny. I couldn't believe how powerful, how strong she was," Rah said. "She was helping other flight attendants even outside the plane."
Lee refused medical attention after the crash, but later learned she had broken her tail bone in the accident.
San Francisco Police Lt. Gaetano Caltagirone was one of the police officers who responded to the crash. He says smoke quickly filled the cabin of the mangled plane.
"You could smell the smoke and the jet fuel and the burned grass that's out there," he said.
ABC News' Matt Hosford, Joohee Cho, ABC News Radio and The Associated Press contributed to this report.