New data on the the missing Malaysian jet with 239 people aboard shows the flight ended with no survivors, Malaysian Prime Minister Najib Razak confirmed Monday.
"It is with deep sadness and regret that I must inform you that according to this new data flight MH 370 ended in the southern Indian Ocean," the prime minister said in a press conference.
Family members of the passengers were informed by a short text message from Malaysian Airlines just before the prime minister spoke.
"We have to assume beyond any reasonable doubt that MH370 has been lost and that none of those on board survived," it read.
This new certainty over the fate of the missing plane comes after an analysis of new satellite data by British company Inmarsat. They were able to she more light on the path of Flight 370 and zero in on its last position.
Floating debris was also spotted in the same area, about 15,000 miles off Australia's coast. Search planes and ships are on their way.
Now that authorities believe they've located Flight 370, the search for its black box begins.
"The real answers to the mystery of this airplane crash lie 700 miles back to the West wherever the airplane hit the water, at the bottom of the ocean," Col. Steven Ganyard said. "The effort needs to shift far to the West and get there before the batteries run out."
The batteries run out in about five days. On Monday morning, the U.S. Navy announced that it's sending a black box locator to the region to help in the search.