The ATR twin-turbo fell into the Mekong River about 4 p.m. as it was coming in to land at the airport in Pakse, in Champassak province in southern Laos, the Bangkok Post reported.
The plane had left Vientiane about 2:45 p.m.
The dead included 39 passengers and five crew members. Five of the dead were Thai, a spokesman for the Thai foreign ministry said.
Notable deaths of 2014 [PHOTOS]
China overhauls legal system, at least on paper