The pilots of Asiana Airlines Flight 214 were not tested for drugs or alcohol after Saturday's crash, National Transportation Safety Board Chairwoman Deborah Hersman said in a press conference in San Francisco Tuesday.

Hersman stated that while U.S.-based crews are required to be tested, this standard does not apply to foreign carriers post-accident. Hersman said the NTSB defers to the countries in which the air carriers are based. In this instance, South Korea would make the call on testing the pilots.

As previously reported, Capts. Lee Kang-kook and Lee Jeong-min were at the helm when the plane crashed on the runway at San Francisco International Airport. Lee Kang-kook, the “flying pilot,” according to Hersman, had logged only 43 hours flying the Boeing 777. His partner, Lee Jung-min, was more experienced in the aircraft, with more than 3,220 hours clocked.

Hersman also told reporters that there were three pilots in the cockpit at the time of the crash, and one pilot in the cabin. The third pilot came in to monitor the landing. “We need to understand what was going on in the cockpit,” Hersman said.

When asked if any flight attendants were incapacitated during the crash, Hersman replied that two flight attendants in the rear of the plane were ejected from the aircraft during impact. They were found off to the side of the runway away from the plane. They escaped with minor injuries, but were traumatized from the experience.

The main landing gear of the aircraft struck the seawall at the end of the runway at SFO, which caused the tail to break off and sent fuselage skidding across the immediate area, according to the Associated Press.

Hersman said that the post-crash fire was due to a ruptured oil tank which leaked fuel.

During the press conference, Hersman defended the NTSB against claims made by the Air Line Pilots Association. The union has been highly critical of the information released thus far, which suggests pilot error. In response, Hersman stressed the need for transparency in this situation. “We work for the traveling public,” Hersman said. “We believe it’s important to show our work and tell people what we are doing.”

Asiana Airlines Flight 214 crashed at San Francisco International Airport on Saturday, killing two teenage girls from China and injuring nearly 200 passengers and crew.