The NTSB has also begun interviewing the four Asiana Airlines pilots at the helm of plane, which may take some time because of a language barrier.
"The pilots speak Korean. English is the universal language. In aviation, everyone is expected to be proficient enough in English to communicate with air traffic control in any country in the world. So we are certainly going to be looking to see if there was any miscommunication or misinformation that was provided," said NTSB chairwoman Deborah Hersman.
The NTSB will also be looking at their 72-hour work histories and rest periods, recent illnesses, health issues, and anything else that could affect human performance.
The head of Asiana has said there were no mechanical failures, and the National Transportation Safety Board says it has recovered very good information from the cockpit voice recorder in the seconds leading up to the crash. That information points attention to the pilots.
Asiana spokeswoman Lee Hyo-min said the pilot at the controls, identified as Lee Kang-kook, had nearly 10,000 hours flying other planes but only 43 in the 777, a plane she said he still was getting used to flying. She also said Lee was fully licensed and had flown a 777 plane nine previous times to other airports. However, he was in training, and this was his first time landing a 777 plane at San Francisco Airport.
Lee flew with an experienced Boeing 777 pilot mentor, in accordance with world standard, the spokeswoman said.
Landing at SFO can be tricky, as runways are surrounded by water. There is a sea wall to prevent planes from going into the water, but planes coming in must clear that first before making contact with the runway. Flight recorder data reveals that Flight 214's air speed was at 106 knots; ideal speed is 137 knots.
First responders on Monday described what they witnessed when they rushed into the plane to pull passengers to safety.
"The conditions inside the plane were changing very rapidly. When we first got back there and saw these people, it was actually pretty clear in there. There was not a lot of smoke, there was not a lot of fire," said San Francisco Fire Lt. Christine Emmons. "But by the time we removed the final victim, the conditions were that the fire was banking down on us, and we had heavy black smoke. So I feel very lucky and blessed that we were able to get those people out in that time."
Witnesses have said that impact appeared to be just short of the runway. The tail was completely sheared off, and fire broke out.
"We see accidents that occur with very experienced pilots, and we see accidents that occur with pilots that have little experience. So we want to understand what kind of experience the pilots had, what's going on and again, we will focus on the communications between the two crew members," said NTSB Chairwoman Deborah Hersman.
Details about the evacuation process are also coming to light. On Sunday, cabin manager Lee Yoon-hye described several dramatic moments in the remarkable evacuation that saved 305 of the 307 people on the plane.
She said even before the plane began filling with smoke, two evacuation slides on the doors inflated inside the cabin instead of outside, pinning two flight attendants to the floor. Other crew members used axes to deflate the slides while ushering passengers out.
In the first comments by a crew member since the crash, Lee also said one flight attendant put a scared elementary schoolboy on her back and slid down a slide. Also, she said a pilot helped another injured flight attendant off the plane after the passengers escaped. Lee herself worked to put out fires and usher passengers to safety despite a broken tailbone. She said she didn't know how badly she was hurt until a doctor at a San Francisco hospital later treated her.
While two teenagers from China lost their lives in the crash, it is remarkable that more weren't killed. As of Monday morning, 51 people were still hospitalized, and eight remained in critical condition.
The two passengers killed were 16-year-old students from China on their way to Southern California. Investigators are now looking into whether one may have been struck and killed by emergency workers rushing to the scene.
NTSB says it too is looking at video of the response, but doesn't have any answers yet.
"They shared with me that it wasn't conclusive, so we really need to work and talk to people, conduct initial interviews and let the coroner do their work," said Hersman.
The Associated Press and ABC News contributed to this report.