The agency said after the crash landing, passengers were told to stay seated while the crew contacted the control tower. People did not begin fleeing the aircraft until 90 seconds later when a fire was spotted outside the plane.
"He stated he looked to 2R, and he could see fire outside of the window. He sent the flight attendant who was sitting with him at 2L up to the front of the cabin to let them know that there was fire, and that they needed to evacuate," said NTSB chairman Deborah Hersman.
At that point, the doors were opened and escape slides were inflated. Two flight attendants were pinned by slides that inflated inside during the impact.
The NTSB said three flight attendants were ejected from the aircraft. All three were seated in the back of the plane. They remain hospitalized after surviving the ordeal. They have not yet talked to investigators.
The flight attendants who were not seriously hurt tried to get everyone off the plane as quickly as possible, according to the NTSB. They also grabbed fire extinguishers and began putting out the flames in order to help one flight attendant who was pinned in a seat.
Six members of the crew, one of whom was in a wheelchair, attended a news conference Wednesday afternoon. Flight attendant Yoon Hye Lee spoke on behalf of the group through a translator.
"I hope for all the families who have suffered losses from this accident to recover as quickly as possible, and they are all in my prayers," she said.
Six of the 12 crew members are still in the hospital. The NTSB says Lee Gang-kuk, the pilot who was learning to land the 777, and Lee Jeong-Min, the pilot who was instructing him, both had eight hours of sleep the night before the flight, indicating they were well-rested.
While the two pilots had years of aviation experience, this mission involved unfamiliar duties, and it was the first time they had flown together.
The NTSB "is definitely going to focus on what type of policy Asiana had in terms of crew pairing," former NTSB Chairman James Hall said. "That's what the airline needs to do, be responsible so that in the cockpit you're matching the best people, especially when you're introducing someone to a new aircraft."
Hersman said the pilot told investigators he was blinded by a light at about 500 feet, which would have been 34 seconds before impact and the point at which the airliner began to slow and drop precipitously. She said lasers have not been ruled out.
It was unclear, however, if the flash might have played a role in the crash. The pilots used many automated modes on the descent. Investigators are looking at the automation onboard the aircraft and will talk to Boeing to get a better understanding.
The Associated Press contributed to this report.
