Facebook chief operating officer Sheryl Sandberg was almost a passenger on the Asiana Airlines plane that crash landed in San Francisco on Saturday.

Sanberg, on her Facebook page, said that she switched flights at the last minute so she could use her airline miles to pay for her family's tickets.

"My family, colleagues Debbie Frost, Charlton Gholson and Kelly Hoffman and I were originally going to take the Asiana flight that just crash-landed.

"We switched to United so we could use miles for my family's tickets.

"Our flight was scheduled to come in at the same time, but we were early and landed about 20 minutes before the crash. Our friend Dave David Eun was on the Asiana flight and he is fine," said Sandberg on her Facebook page.

Two people were killed, 181 were injured and one was still unaccounted for Saturday in the crash landing of an Asiana Airlines Boeing 777 at San Francisco International Airport.

It was the first fatal crash of a passenger jet in 20 years for Asiana, South Korea's second-largest airline.

In June 1993 an Asiana Boeing 737 crashed into a mountain in South Korea, killing 68.