NEW DETAILS: Glacial collapse triggers CATASTROPHIC floods near China-Nepal border

>> Ashley: A FOX NEWS ALERT, POLICE SAY AT LEAST 273 BODIES. HAVE BEEN FOUND AND 1300 STILL. MISSING AFTER FLOODS TRIGGERED. MASSIVE LANDSLIDES. >> Todd: 3300 FIRST RESPOND ERS. ARE ASSISTING. WARN YOU, NEXT VIDEO IS GRAPHIC.

ROCK LANDSLIDE NEAR THE BORDER. SENT THAT WALL OF WATER RACING. DOWNSTREAM. WE'VE SEEN COUNTLESS PIECES OF. VIDEO JUST LIKE THAT. HERE TO BREAK IT DOWN IS. METEOROLOGIST ADAM KLOTZ. LIKE NOTHING I HAVE EVER SEEN. >> Adam: NOTHING I HAVE EVER. SEEN. IT HAPPENS ON SMALLER SCALES. I HAVE CLIMBED ON GLACIERS, THERE IS WATER AND ICE.

GLACIERS ARE FREEZING AND. MELTING AGAIN AND AGAIN AND. UNDER THEM YOU CAN GET WATER. WHAT WE THOUGHT WAS SEISMIC. ACTIVITY WAS THAT BIG LANDSLIDE. FALLING OFF. YOU GET THAT RUSHING DOWN INTO. THE WATERWAYS AND RELEASES WATER. AND IT IS RELEASING ROCK GOING. DOWN SOME MOUNTAINS AND THERE IS. A LOT OF ENERGY AND ICE BEGINS. TO MELT MORE AND MORE UPON. RAIDLY AND ENTERS SOME RIVERS.

ALL OF A SUDDEN NARROW RIVERWAYS. IS WHAT YOU ARE SEEING WALLS OF. WATER. WATER WAS RELEASED AND ALL THAT. ICE BREAKS LOOSE, FALLING DOWN. AND SUDDENLY YOU SEE HOW NARROW. THAT CAN BE AND GET A ABSOLUTE. WALL OF WATER. SCARY SITUATION. GLACIERS, YOU ARE TALKING ABOUT. FALLING TENS OF THOUSANDS OF. FEET INTO NARROW AREAS.

ONCE THAT MELTS, IT FILLS THAT. LITTLE RIVER VALLEY AND YOU GET. THAT WALL OF WATER. THIS DOES HAPPEN, ON SMALL. SCALES, YOU DON'T SEE SO MUCH. BREAK OFF ALL AT ONCE AND YOU DO. IT WITHOUT RAIN. >> Ashley: THE VELOCITY, PEOPLE. HAD SECONDS TO REACT. >> Todd: GEO SCIENTIST SIMON. COOK IS JOINING US. THE WORD I KEEP READING.

PULVERIZED. A BLOCK OF ICE 500 FEET WIDER. THAN EMPIRE STATE BUILDING. PLUMMETED 4000 FEET TO THE. GROUND AND TURNED INTO A TORRENT. OF WATER. EXPLAIN WHAT HAPPENED AND WHY. THAT HAPPENED, THIS SEEMS. UNCONSCIONABLE TO NORMAL PEOPLE. LIKE ASHLEY AND ME AND THE REST. OF US. >> NICE INTRODUCTION THERE.

AFTER WORK, I'M AFRAID, WE THINK. A BLOCK OF ICE 0.2 SQUARE. KILOMETERS FELL 1300 METERS, BEST PART OF A MILE, FELL INTO. THE VALLEY BELOW. YOU ARE RIGHT TO USE THE WORD. PULVERIZE, THIS MASSIVE GLACIER. OF ICE WAS BROKEN UP INTO. SMALLER PIECES, RELEASING HUGE. VOLUME OF WATER. IT IS A MYSTERY. IT IS SUBSTANTIAL ICE AVALANCHE,

IT IS A MYSTERY HOW THAT. TRANSLATES INTO SUCH A BIG. FLOOD. WE THINK THERE IS PROBABLY OTHER. WATER INVOLVED. IT IS POSSIBLE THERE IS A LOT OF. DEAD AND DECAYING ICE IN THE. VALLEY AND MELTING AND RECEDING. BECAUSE OF CLIMATE CHANGE AND. LOOSE DEBRIS AND DECAYING ICE. THAT COULD HAVE BEEN IN THIS ICE. AVALANCHE AND THAT IS HOW VOLUME. OF WATER AND DEBRIS INVOLVED IN.

THIS. LOOKING AT SATELLITE IMAGES, SORRY, GO AHEAD. >> Ashley: GO ON, SIMON. >> I WAS LOOKING AT SEATTLE DAY. BEFORE AND DAY OF EVENT, LOOKS. LIKE JUST BEFORE THE EVENT IN. VICINITY THAT THE GLASS BROKE. OFF, HAD DESCENT AMOUNT OF SNOW. COVERING AND DAY AFTER, DAY OF. FLOOD, SNOW COVER DISAPPEARED. ONE THING WE'RE INVESTIGATING IS.

POSSIBILITY OF SOME SORT OF HIGH. ALTITUDE WARMING EVENT REMOVED. TO LET SNOW COVER AND THAT SNOW. COVER IS MELTED AND FOUND WAY. THROUGH CREVISES IN HOPES TO. LUBRICATE IT TO SLIDE OFF. THERE IS A VERY SHARP BREAK. WHERE THE GLACIER IS BROKEN OFF. AND WHICH IS KIND OF ANALOGOUS. TO OTHER EVENTS WE'VE SEEN IN. THE HIMALAYA IN RECENT YEAR.

WHERE BEDROCK ALSO FAILED. IT COULD BE COMBINATION OF. GLACIER FAILING AND BEDROCK. BENEATH IT, ADDING MORE MATERIAL. INTO THE FLOOD. >> Ashley: IS THIS SOMETHING. SCIENTISTS KNEW COULD HAPPEN? IS THIS AN AREA THEY WERE. WATCHING? MORE I HEAR FROM ADAM AND YOU, IT DOES NOT SOUND LIKE IT. BASED ON LOCATION, I'M CURIOUS. IF YOU THOUGHT THIS IS SOMETHING. THEY COULD BE WATCHING?

>> SCIENTISTS, THERE ARE. SCIENTISTS AROUND THE WORLD. DOING LOTS OF DIFFERENT PROJECTS. AND MONITORING THESE SORTS OF. LOCATIONS. IT IS LIKE LOOKING FOR A NEEDLE. IN A HAYSTACK, SO MANY DIFFERENT. GLACIERS, IT IS IMPOSSIBLE TO. MONITOR ALL OF THEM AND ALL THE. DIFFERENT TRIBUTEARIES OF THEM. IN IMMENSE DETAIL. THIS LOOKS LIKE IT IS A HANGING. GLACIER, THOUSANDS OF FEET ABOVE.

THE BAY, BELOW THE STEEP. INCLINE, THAT IS REMINISCENT OF. GLACIERS IN THIS REGION. IT IS LIKE LOOKING FOR A NEEDLE. IN A HAYSTACK. YOU CAN COME UP WITH CURSORY. RISK ASSESSMENT FOR THESE SORTS. OF THINGS, I DON'T KNOW THAT. ANYONE WAS LOOKING SPECIFICALLY. AT THIS PARTICULAR GLACIER. LAST YEAR, LAST JULY, A GLACIAL. LAKE BURST AND FLOODED THE SAME.

VALLEY AND I THINK UNFORTUNATELY. DESTROYED THE FRIENDSHIP BRIDGE. BETWEEN NEPAL AND CHINA AND I. THINK KILLED 18 PEOPLE, BUT THAT. WAS ON A MUCH SMALLER SCALE THAN. WE SAW IN THE HORRIFIC FOOTAGE. CIRCULATING YESTERDAY AND TODAY. >> Todd: HOW AT RISK ARE RESCUE. CREWS? THERE ARE BLOCKAGES UPSTREAM. THAT COULD RELEASE EVEN MORE.

WATER. >> REALLY GOOD POINT. THERE ARE ALL SORTS OF SECONDARY. HAZARD SAYS. JUST BECAUSE THERE IS ICE. AVALANCHE DOES NOT MEAN. SURROUNDING LANDSCAPE IS NOT. STABILITY. THAT COULD BE MORE ICE AVALANCHE. SAYS ON THE WAY. FLOODS US ARE SEEING ON IMAGERY. WILL UNDER CUT VALLEY SIDE. POTENTIALLY RELEASING MORE.

LANDSLIDE SAYS. THERE IS LOTS OF IMAGES OF. RESCUE WORKERS WADING THROUGH. MUD, WHICH IS INCREDIBLY. DANGEROUS, THERE ARE SECONDARY. HAZARDS THAT WILL COME INTO PLAY. AND WE HOPE RESCUE WORKERS ARE. SAFE AS THEY CAN BE. >> Todd: SIMON COOK, THANK YOU, I KNOW YOU ARE T.