( CNN ) -- The National Transportation Safety Board has wrapped up its on-scene work as part of its investigation of the Asiana Flight 214 crash at San Francisco airport , the agency said Monday . Investigators are done examining the runway and the wreckage , which is now in storage at the airport . But they may still return to examine the plane again if needed . Most of the government probe has moved to Washington where investigators will further analyze cockpit voice and data information , piece together mountains of records and run other crash material through NTSB labs . Additional interviews with first responders is the only work still being done in San Francisco , the NTSB said . The flight carrying 291 passengers and 16 crew took off from Shanghai and stopped in Seoul before heading to San Francisco . It was an unremarkable flight prior to final approach that should have been routine in ideal flying conditions . Asiana regularly flies into San Francisco . But flying too slow and too low as it neared the airport on July 6 , the pilots of the big jetliner sought to abort the landing at the last second . The plane slammed into the sea wall and then the runway , its tail breaking off and the fuselage full of people spinning down the tarmac . Three passengers , all girls , died in the first notable U.S. air crash in four years . More than 180 people were hurt and the rest walked away relatively unscathed . Most were able to escape before the plane erupted in smoke and flames . The runway was littered with plane parts , bags , and a carpet of other debris that was examined in varying detail by investigators . Investigators do not expect to know for several months at least what exactly caused the crash . But early information from the board has centered heavily on the actions of the crew . The pilot at the controls was training on the 777 although he was experienced at flying other big Boeing and Airbus jets and had landed in San Francisco previously in those planes .
Investigators are done with their work at the airport . The Asiana plane 's wreckage is still there for future examination . The NTSB is doing further work with first responders . The May 6 crash of the Boeing 737 killed four people .