Three people died and dozens of others were injured on July 6, 2013, when Asiana Flight 214 clipped a seawall while landing.
According to the Foreign Air Carrier Family Support Act of 1997, foreign airlines are required to assure that in the event of an aircraft accident resulting in major loss of life, they will provide various services to passengers and their families. This includes publicizing and staffing a toll-free telephone number for families and notifying families as soon as possible after the airline has verified the identity of a passenger, whether or not the names of all of the passengers have been verified.
In a statement, the Department of Transportation said, "For approximately one day following the crash, Asiana failed to widely publicize any telephone number for family members of those onboard, and the only number generally available to the public that family members could call was Asiana's toll-free reservations line," adding that locating even that number took "significant effort."
The statement went on to say that the airline took two days to contact the families of just 75 percent of the passengers, and several families were not contacted until five days after the crash.
Many of the families live in South Korea or China, and the airline was their main source of information on the crash half a world away.
The Department of Transportation also noted in the statement that it took two days to send trained personnel to San Francisco, "initially lacked an adequate number of staff able to communicate in the languages spoken by the flight's passengers, and had no pre-existing contract for the cleaning and returning of passenger property."
In a statement emailed to ABC News, Asiana spokeswoman Hyomin Lee said the airline "provided extensive support to the passengers and their families following the accident and will continue to do so."
The National Transportation Safety Board is still investigating the cause of the crash.
Family members of some passengers have sued the airline, alleging coach passengers suffered more serious injuries than business class travelers because of different seatbelt configurations. Lawsuits also claim that Asiana failed to properly train its pilots and that the plane's auto-throttle was inadequate.
The Associated Press contributed to this report.