Deadly mudslide devastates China-Nepal border

L. 30 BILLION, 231 BILLION NOW THE. ESTIMATE. THANK YOU BOTH. ♪ ♪. >> Trace: BREAKING TONIGHT, A. MASSIVE RESCUE EFFORT UNDERWAY. ALONG THE BORDER OF NEPAL AND. CHINA AFTER MUDSLIDES TRIGGERED. CATASTROPHIC FLASH FLOODING. THEY HAVE KILLED AT LEAST 160. PEOPLE. CHIEF WASHINGTON CORRESPONDENT. MIKE EMANUEL IS LIVE WITH MORE. ON THE DESPERATE SEARCH FOR. SURVIVORS. GOOD EVENING. >> Reporter: GOOD EVENING. THE DEATH TOLL IS LIKELY TO RISE. AS HUNDREDS OF TOURISTS, WORKERS, AND OTHERS REMAIN.

MISSING. A WARNING, SOME OF THIS VIDEO IS. DISTURBING TO WATCH. FOOTAGE SHOWS ROADS DESTROYED. AND BUILDINGS BURIED BY EXTREME. FLASH FLOODING. WATER RUSHING DOWN THE. MOUNTAINS, WIPING OUT EVERYTHING. IN ITS PATH. THE U.S. GEOLOGICAL SURVEY SAYS. THE LANDSLIDE WAS THE EQUIVALENT. OF A 5.2 MAGNITUDE EARTHQUAKE. OFFICIALS SAY AT LEAST 344. NATIONALS ARE MISSING AND THAT. REPORTEDLY INCLUDES 47. AMERICANS. THE INCIDENT TAKING PLACE ON THE.

HIMALAYAN BORDER BETWEEN NEPAL. AND CHINA CONTROLLED TIBET. FIRST RESPONDERS REACTED QUICKLY. TO SAVE LIVES OF THOSE WHO COULD. BE SAVED. A PILOT DESCRIBING THE HORROR OF. THIS NATURAL DISASTER. >> EVEN THE GUY WHO WAS FLYING. WITH ME, 20 YEARS OF EXPERIENCE, HE WAS DEVASTATED. IT'S HUGE. >> YOU CAN SEE EVERYTHING BEING. SWEPT AWAY. >> Trace: SECRETARY OF STATE. MARCO RUBIO SAYS THE U.S. STANDS.

READY TO SUPPORT NEPAL WITH. NEEDED HUMANITARIAN ASSISTANCE. >> Trace: MIKE EMANUEL LIVE IN. D.C. THANK YOU. LET'S BRING IN FOX NEWS. METEOROLOGIST ARI SARSALARI. I WAS LOOKING AT THE PICTURES, I. DON'T KNOW WHAT HAPPENED. IT SEEMED LIKE A LOT OF THESE. PEOPLE WERE JUST ABSOLUTELY. TAKEN OFF GUARD. WHAT DO YOU MAKE OF THIS? >> IT'S JUST UNBELIEVABLE. IT'S THE SAME PROCESS AS WE SEE. SOMETIMES IN THE WESTERN U.S. SOMETIMES YOU GET A BURN SCAR.

AND A LOT OF HIGH RAIN, THE. WATER STARTS RUSHING DOWN. THE IDEA IS THIS IS THE. HIMALAYAS. THE MOUNTAINS ARE SO. RIDICULOUSLY HIGH, THE LATEST. THEORY ON THIS IS THAT THERE IS. A HUGE CHUNK OF GLACIER THAT. CAME OFF IN HIGH ELEVATION AND. JUST CRASHED DOWN SEVERAL. THOUSAND FEET, HIT THE GROUND, AND WHEN IT DID THAT IT WAS DOWN. IN THE RIVERBED AND THAT CREATED. THIS HUGE TIDAL WAVE. SO YOU CAN JUST IMAGINE THE.

FORCE OF GRAVITY WHEN YOU'RE. DEALING WITH MOUNTAINS. >> Trace: IT'S ONE OF THOSE. THINGS WHERE YOU LOOK AT THIS. AND THINK, OH, MY GOODNESS. WITH THE WATER AND THE MUD, THEY. DO IMMENSE DAMAGE. AND WHEN YOU TALK ABOUT SOME OF. THESE EVENTS LIKE TORNADIC. ACTIVITY, THAT'S NOT THE WIND AS. MUCH AS THE STUFF INSIDE. THE SAME THING HERE CAN BE VERY. HARD FOR RESCUE AND RECOVERY. >> IT REALLY IS. THERE'S SO MUCH STUFF IN THAT. DEBRIS FLOW COMING DOWN.

OVER TIME IT APPARENTLY. ACCUMULATES A LOT OF DEBRIS IN. ADDITION TO THE HUMONGOUS AMOUNT. OF ICE. JUST THINK ABOUT HUMONGOUS. BOULDERS. IF YOU'VE GOT A 2000-FOOT WIDE. CHUNK OF ICE THAT COMES DOWN, CRASHES DOWN 4000 FEET INTO THE. WATER AND YOU HAVE THAT MUCH. TERRAIN, SO GRAVITY IS GOING TO. BE WORKING EXTRA IN THAT PART OF. THE WORLD. JUST SENDS THIS CRAZY TIDAL WAVE. DOWN. SOME OF THE CRAZIEST VIDEO I'VE. SEEN SINCE THE 2011 TSUNAMI.

SUPER SCARY. >>.