Vietnamese authorities say they detected plane’s last signal ← Related Article Visit The Boston Globe Share on Twitter Share on Facebook Comment on this Scroll to top of page Ng Han Guan/AP Airport workers in Beijing helped a woman in tears to a bus waiting for relatives of people aboard a missing Malaysian airliner. Lai Seng Sin/AP Malaysia Airlines says a flight headed from Kuala Lumpur to Beijing lost contact over the South China Sea early Saturday. KIM KYUNG-HOON/Reuters A relative of a passenger who was aboard the flight cried as she talked on her cellphone in Beijing. MARK RALSTON/AFP/Getty Images The flight was carrying 239 people, including four Americans. Lai Seng Sin/AP CEO Ahmad Jauhari Yahya spoke during a press conference outside Kuala Lumpur. Ng Han Guan/AP A man who says he has relatives who were on the plane spoke to journalists at Beijing International Airport. MARK RALSTON/AFP/Getty Images People stood beside the arrival board in Beijing, which shows the missing flight at the top.