>>> IT WAS ONE OF THE DEADLIEST NATURAL DISASTERS IN MODERN TIMES.

20 YEARS AGO MASSIVE TSUNAMI TRIGGERED OFF THE COAST OF INDONESIA KILLED MORE THAN 200,000 PEOPLE IN 14 COUNTRIES.

A NEW DOCUMENTARY CALLED "TSUNAMI: RACE AGAINST TIME" LOOKS BACK AT THAT DEVASTATING TODAY.

THE 20th OF DECEMBER, 2004.

HERE'S A BIT FROM THE TRAILER.

>> PEOPLE WERE ON THE STREET.

SUDDENLY I CAN SEE THIS REALLY HIGH WATER.

AND I WAS JUST LIKE, WHAT IS THAT?

>> WOW.

HARI SREENIVASAN SITS DOWN WITH DIRECTOR DANIEL BOGADO AND BARRY HIRSHORN.

>> THANK YOU BOTH FOR JOINING US.

YOUR NEW DOCUMENTARY, "TSUNAMI: RACE AGAINST TIME," IT'S ABOUT THE DEVASTATING TSUNAMI THAT CAME ACROSS A HUGE SWATH OF THE PLANET ABOUT 20 YEARS AGO.

FIRST, WHAT DREW YOU TO THIS TOPIC?

>> I SUPPOSE IT IS THE 20th INVESTIGATE VERSE.

IT'S DIFFICULT TO BELIEVE IT HAS BEEN 20 YEARS SINCE IT HAPPENED.

I REMEMBER WAKING UP AND THE SCALE OF THE TRAGEDY.

A LOT OF PEOPLE FORGET WE LOST NEARLY A QUARTER OF A MILLION PEOPLE IN ONE DAY.

SO WE HAD THIS IDEA WHICH WOULD BE FOCUSING ON THE DAY ONLY WITH VIDEO ARCHIVE OF THE DAY AND BASICALLY, LISTENING FROM SURVIVORS AND PEOPLE WHO EXPERIENCED THAT.

IT TOOK MANY YEARS TO PUT TOGETHER TOGETHER.

WE THOUGHT IT WAS VERY IMPORTANT TO PUT TOGETHER.

WE TRAVELED TO INDONESIA, SRI LANKA, WE FOUND HUNDREDS OF HOURS OF VIDEO FOOTAGE THAT HAD NEVER BEEN SHOWN BEFORE ANYWHERE.

THAT WAS ONLY THE FIRST PART OF JOB.

AFTER THAT, WE SAW PEOPLE IN THE VIDEO ARCHIVE AND WE WANTED TO FIND THEM AND TRACK THEM DOWN SO WE COULD HEAR DIRECTLY FROM THEM THEIR STORIES.

THAT WAS A WHOLE SEPARATE CHALLENGE.

>> THEN THERE WAS A SHOUT.

THIS IS COMING.

THIS IS COMING.

BUT IT LOOKED LIKE IT'S COMING GENTLY.

SUDDENLY, EVERYBODY STARTED RUNNING.

AND THEN -- >> BARRY, YOU WERE WORKING IN HAWAII AT THE TIME.

8,000 MILES AWAY FROM WHERE THIS EARTHQUAKE, THE TSUNAMI HAPPENED.

YOU WERE WORKING AT THE PACIFIC TSUNAMI WARNING CENTER.

>> WE HAVE A MAGNITUDE 8.

AND WE'RE TRYING TO RIAN LIES THE MAGNITUDE WITH MORE DATA.

AND THEN WE GOT A MAGNITUDE 8.5.

AND ALTHOU YOU THINK OF 8.5 VERSUS 8, SO WHAT, .5, RIGHT?

IT IS A LOG RHYTHMIC SCALE.

EACH DIFFERENCE IN MAGNITUDE IS ABOUT A 30-TIME INCREASE IN ENERGY.

>> SO WE'RE TALKING ABOUT SOMETHING THAT IS ALMOST THE LENGTH OF CALIFORNIA UNDER THE SEA THAT ESSENTIALLY, TWO BIG PLATES ARE SHIFTING UP.

SO WHEN THIS PART OF THE EARTH GOES UP OR DOWN, THAT MEANS, WHAT?

THE WAVE THAT IS A COLUMN OF WATER, SUPER HIGH, ALL THAT ENERGY, LIFTS UP THOSE MILLIONS AND BILLIONS OF POUNDS AND WHATEVER OF WATER AND MAKES THEM FALL OVER?

IS THAT WHAT IS HAPPENING IN A TSUNAMI?

>> IT ESSENTIALLY LIFTS THEM AND LIFTS THEM IN A GIGANTIC PULSE.

ONE OF THE THINGS THAT IS VERY IMPORTANT TO UNDERSTAND WHEN YOU GET TO EARTHQUAKES OF THIS SIZE, THERE IS A FAIRLY COMMON -- A COMMON PERCEPTION THAT EARTHQUAKES OCCUR AT A POINT IN THE EARTH.

AND THE REALITY IS THAT THEY OCCUR ALONG RUPTURED ZONES.

THIS ONE WAS ROUGHLY THE LENGTH OF CALIFORNIA.

SO IF YOU CAN IMAGINE THAT GIGANTIC COLUMN OF WATER THAT YOU IMAGINE, LIFTING, TAKING SUCCESSIVE COLUMNS OF WATER, COMPARABLE TO THAT, OVER A PERIOD OF NINE OR TEN MINUTES, SUCCESSIVELY LIFTING AS THE FAULT RUPTURED TO THE NORTHEAST.

YOU HAVE MULTIPLE TSUNAMI SOURCES THAT ALL COMBINE COMING FROM THIS GIGANTIC FAULT.

>> I SAW AN ELDERLY COUPLE.

I THOUGHT, I HAVE TO GO DOWN THERE AND TO HELP THEM.

THIS ELDERLY COUPLE WERE HANGING ON TO THE RAILING.

I TRIED TO REACH THEM.

AND THEY JUST DISAPPEARED.

>> BARRY, THERE ARE PERIODS IN THE DOCUMENTARY WHERE YOU CAN SEE HOW REALLY ANGUISHED YOU AND YOUR STAFF ARE, REALIZING THAT YOU JUST DON'T HAVE THE INFORMATION FROM THE OTHER SIDE OF THE PLANET THAT COULD HELP YOU HELP MORE PEOPLE.

WHAT WAS, WHAT WERE THE THINGS THAT STARTED TO, YOU KNOW, WHAT WERE THE PIECES OF INFORMATION THAT STARTED TO TRICKLE IN WHERE YOU UNDERSTOOD, REALLY, THE MAGNITUDE FOR LACK OF A BETTER TERM WHAT WAS HAPPENING SO FAR AWAY?

>> THE ONE THAT REALLY DROVE THE POINT HOME TO ME WAS A TRAIN, WHICH IS NOT A FEATHERWEIGHT OBJECT.

A TRAIN IS A VERY MASSIVE, MASSIVE THING.

INLAND, FROM THE TSUNAMI, IN SRI LANKA.

SOMETHING LIKE TWO OR THREE HOURS TRAVEL TIME AWAY FROM THE SOURCE.

THAT DROVE THE POINT HOME THAT WE WERE DEALING WITH SOMETHING EXTREMELY -- I WOULD SAY, THERE WAS AN ORDER OF MAGNITUDE JUMP IN SCIENCE SPEAK IN OUR AWARENESS.

AND I WOULD LIKE TO POINT OUT THAT AT THAT TIME, THE DIRECTOR DID SOMETHING WHICH I SUPPOSE IS AN ADVANTAGE OF HAVING SCIENTISTS ON DUTY FOR THESE EVENTS.

HE'S A SEISMOLOGIST AND A WATER LEVEL PERSON, AND HE WAS ABLE TO GENERATE ON THE FLY A MAP THAT SHOWED THE TSUNAMI TRAVEL TIMES EVERY HOUR FOR THE INDIAN OCEAN, WHICH OF COURSE, WE DID NOT HAVE.

AND SO THIS COMBINATION OF THIS UBER REALIZATION OF MAGNITUDE COMBINES WITH A TOOL THAT, THE VALUE IS INFINITELY VALUABLE IN THAT SITUATION.

YOU CAN NOW FOCUS THE ENERGY AND PERSONNEL YOU HAVE ON PLACES AHEAD OF THE WAVE CRITICAL.

>> DANIEL, BARRY MENTIONED THIS TRAIN.

THE STORY OF THE TRAIN IN SRI LANKA IS SO FASCINATING BECAUSE WE TAKE FOR GRANTED THAT WE CAN TEXT EACH OTHER AND TELL EACH OTHER SOMETHING DOWN THE ROAD OR AHEAD OF YOU.

THIS WAS ONE OF THE WORST TRAIN DISASTERS IN HUMAN HISTORY AND SO FEW PEOPLE MADE IT OUT OF THERE.

YET YOU WERE ABLE TO TRACK DOWN ONE OF THE SURVIVORS AND REALLY HAVE HER SHARE THIS INCREDIBLY POWERFUL STORY OF HER OWN.

>> YES.

AN INTERESTING DETAIL ABOUT THAT TRAIN IS THAT THEY ACTUALLY DID GET WARNING ABOUT IT, THAT THEY WERE HEADING STRAIGHT TO THE TSUNAMI.

BUT UNFORTUNATELY, BY THE TIME THEY GOT THE WARNING AND THEY TRIED TO CALL THE TRAIN, THERE WAS NO WAY TO COMMUNICATE WITH ANYBODY ON THE TRAIN.

SO THE PEOPLE IN THE STATION, JUST AS IT LEFT, HAD A WARNING.

IF IT HAPPENED TODAY, THEY WOULD BE ABLE TO PASS ON THE COMMUNICATION.

AND YES, THERE WERE SO MANY OF THESE CONTRIBUTORS, JUST AN INCREDIBLY, THE CONTRIBUTION THAT CAME FROM THWART.

SHE TALKED ABOUT THE RELATIONSHIP WITH HER MOTHER WHO WAS ON THE TRAIN AND THE EVENTS THAT TRANSPIRED.

SO IN A WAY, THE WHOLE PROJECT, BECAUSE IT IS LARGELY VOICES FROM PEOPLE WHO SURVIVED WHO RUN MINUTE BY MINUTE THE EVENTS THAT HAPPENED TO THEM.

IT TAKES A LOT OF COURAGE TO DO THAT.

A LOT OF COURAGE TO GO BACK AND REVISIT WHAT IS THE WORST DAY OF THEIR LIVES, WITHOUT A DOUBT.

I GUESS THE PITCH WE GAVE TO THEM, WHAT WE WERE TRYING TO DO WITH THIS, WE WERE TRYING FIRST OF ALL TO CREATE SOMETHING FOR THE HISTORICAL RECORD.

FOR FUTURE GENERATIONS TO LOOK BACK AND UNDERSTAND THIS IS WHAT HAPPENED THAT DAY.

AND THEN THE SECOND REASON WAS FOR IT TO SERVE AS A MEMORIAL FOR THE LIVES THAT WERE LOST.

AND HOPEFULLY FOR PEOPLE TO BECOME MORE EDUCATED ABOUT TSUNAMIS.

I THINK IF THERE WAS GREATER KNOWLEDGE ABOUT THE RED FLAGS, ABOUT THE WARNING SIGNS, MANY, MANY MORE LIVES COULD HAVE BEEN SAVED.

>> THE LAYER OF CATASTROPHIC DAMAGE THAT CAME AFTER THE FIRST WAVE AND THE SUBSEQUENT WAVES.

YOU WERE ABLE TO CAPTURE THAT IN SO MANY LOCATIONS.

>> I THINK THERE ARE A LOT OF MYTHS AND MISUNDERSTANDINGS SURROUNDING TSUNAMIS FROM WHAT WE SEE ON TELEVISION AND IN FILMS.

A GIGANTIC WAVE, THE SIZE OF A CITY COMING.

IT'S SIMPLY NOT LIKE THAT.

WE FOLLOWED THE EXPERIENCES OF A WOMAN WHO WAKES UP AND WHEN SHE GOES OUT OF HER HOTEL ROOM, THE FIRST WAVE HAS ARRIVED ALREADY.

SO THERE'S JUST WATER EVERYWHERE.

PEOPLE ARE CONFUSED.

A LOT OF PEOPLE DON'T UNDERSTAND AS THE WATER IS HEADING BACK THAT THAT MEANS ANOTHER WAVE IS COMING.

AND A LOT OF PEOPLE CONGREGATE ON THE BEACH WONDERING WHAT'S GOING ON.

WHEN ALL OF THOSE ARE RED FLAGS THAT THEY SHOULD LEAVE.

THEY SHOULD FIND HIGHER GROUND.

ANOTHER WAVE MIGHT COME AND ANOTHER ONE AND ANOTHER ONE.

BY TAKING THE AUDIENCE THROUGH THAT JOURNEY SO THEY SEE MINUTE BY MINUTE HOW IT PLAYED OUT.

WE HOPE IT IS IN A WAY, EDUCATIONAL FOR PEOPLE.

WHEN THEY ENCOUNTER THE SAME THING, THEY HAVE A MUCH BETTER IDEA WHAT TO DO.

>> BARRY, HOW ARE WE TODAY AS A PLANET COMPARED TO WHERE WE WERE 20 YEARS AGO IF RIGHT NOW A TSUNAMI WAS TO BE HAPPENING BECAUSE OF AN EARTHQUAKE SOMEWHERE FAR AWAY?

>> BETTER THAN WE WERE THEN.

THIS EARTHQUAKE SPARKED A REVOLUTION IN SEISMOLOGY.

A REVOLUTION IN SEISMOLOGY SCIENCE WHICH IS ALSO COUPLED WITH A REVOLUTION THAT WOULD HAVE HAPPENED ANYWAY, AS WE ALL KNOW IN COMMUNICATIONS, IN SENSOR TECHNOLOGY, COMPUTER TECHNOLOGY.

WE HAVE VERY, VERY FAST METHODS BASED ON SEISMIC INSTRUMENTS AND ADVANCES, AND ALL THE ABOVE THAT USED THE INITIAL ARRIVING ENERGY.

WE CAN NOW TELL YOU IT IS A 9.

WE COULDN'T HAVE SAID IT WAS A 9 BEFORE IT WAS COMPLETE, BEFORE THE EVENT WAS OVER.

WHICH WOULD HAVE GIVEN EVEN THE CLOSEST COAST SOME WARNING.

MAYBE FIVE OR TEN MINUTES WHICH IS COMPLETELY UNHEARD OF BACK THEN.

IT IS JUST NO COMPARISON.

THE OTHER CASE BESIDES THIS IS THE MUCH, MUCH MORE DIFFICULT NEAR-FIELD PROBLEM WHERE MOST OF THE CASUALTIES ARE.

AND THERE'S BEEN TREMENDOUS PROGRESS THERE, TOO.

>> DANIEL, YOU WERE ABLE TO FIND SURVIVORS, FIRST RESPONDERS IN THESE PLACES.

SOME OF THEM ARE SO FAR OFF WHERE EVEN THE PEOPLE DIDN'T KNOW WHETHER THEY WOULD BE ABLE TO BE RESCUED OR NOT.

WHETHER THEY WOULD BE STRANDED.

WHAT STOOD OUT TO YOU AS YOU LISTEN TO THEIR STORIES, YOU LOOKED OVER THEIR FOOTAGE?

>> YEAH, WELL, I THINK THAT THAT IS A NUMBER OF THINGS.

WHAT WAS QUITE INTERESTING IS THAT THIS WAS A CATACLYSMIC EVENT WHICH AFFECTED SO MANY PEOPLE IN SO MANY DIFFERENT COUNTRIES.

AND PEOPLE WITH VERY, VERY DIFFERENT BACKGROUNDS.

SO IT WAS AN OPPORTUNITY FOR THE SERIES TO EXPLORE THE PERSPECTIVES OF ALL OF THESE DIFFERENT PEOPLE.

MANY TIMES SPEAKING IN THEIR OWN LANGUAGE.

THEN YOU START SEEING SOME COMMONALITIES, AT LEAST PEOPLE WHO GET SO CLOSE TO THE LINE SEPARATING LIFE FROM DEATH.

IN THOSE LAST MOMENTS, A LOT OF PEOPLE ARE THINKING OF THEIR LOVED ONES, RIGHT?

ALL THE SMALL TRIVIALITIES OF LIFE.

THAT'S SOMETHING THAT YOU SEE ACROSS COUNTRIES, AND ACROSS DIFFERENT BACKGROUNDS.

THEN THE OTHER THING THAT PEOPLE SAW IN THE AFTERMATH WAS THE WAY JUST THAT PEOPLE CAME TOGETHER TO HELP EACH OTHER.

AND AGAIN, THAT WAS A COMMONALITY WHEREVER YOU SAW, THESE ARE ALL THE STORIES IN THAILAND, SRI LANKA, AND INDONESIA.

SO SOMETHING ABOUT THESE EVENTS THAT REALLY MADE CLEAR FOR PEOPLE WHAT REALLY MATTERS.

AND ALSO, IT REALLY SHOWED THE OTHER SIDE OF THE HUMAN CONDITION.

THIS DRIVE THAT WE ALL HAVE TO WANT TO HELP ONE ANOTHER.

AND THAT BECOMES VERY, VERY CLEAR IN SITUATIONS LIKE THE DAY OF THE TSUNAMI.

>> ALL RIGHT.

SEISMOLOGIST BARRY HIRSHORN AND DANIEL BOGADO, IT IS CALLED "TSUNAMI: RACE AGAINST TIME."

YOU CAN WATCH IT STREAMING NOW ON "NATIONAL GEOGRAPHIC" OR DISNEY PLUS.

THANK YOU.