Indonesia's PresidentJoko Widodo walks past debris at the Mutiara Carita Cottages inCarita in Banten province on December 24, 2018, two days after atsunami — caused by activity at a volcano known as the'child' of Krakatoa — hit the west coast of Indonesia'sJava island. (Photo: Sonny Tumbelaka/AFP/Getty Images)

Rescuers hunted for survivors and victims under the rubble ofhundreds of hotels and houses flattened by a deadly tsunami alongIndonesia's Sunda Strait with authorities warning the death tollmay climb from the 373 already confirmed.

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Most of the victims were local holidaymakers staying in thehotels and bungalows along the popular beaches in Lampung andBanten provinces, according to the National Disaster MitigationAgency. More than 1,450 people were injured and dozens are missingafter tsunami waves lashed the provinces late on Saturday, theagency said.

Flank collapse

The deadly wave was likely triggered by flankcollapse — where a section of the volcano givesway — in the south and southwest sides of Mount AnakKrakatau, according to the Energy and Mineral Resources Ministry'sCenter for Volcanology and Geological Hazard Mitigation instatement. Further investigation and analysis are being carried outto learn other factors that may have played a role.

“The tsunami that occurred is a special case and rare in theworld, as well as it's difficult to predict partial collapse in avolcano,” the volcanology agency said in the statement.

The latest in a series of natural disasters to strike SoutheastAsia's largest economy this year is set to pose a fresh challengefor President Joko Widodo as he works to assist the thousands ofpeople displaced amid a presidential election campaign.

The tsunami, coming ahead of the peak holiday season, may alsohurt the all-important tourism industry and weigh on the nation'scurrency, among the worst performers in Asia this year.

Volcanic activity

Indonesia's meteorological agency previously suspected under-seaerosion triggered by volcanic activity of Mount Anak Krakatau, thedisaster mitigation agency's spokesman Sutopo Nugroho said.Authorities failed to pick up the signs of tsunami and alertresidents, catching holidaymakers unawares and increasing thecasualties.

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The death toll could climb as searchers access more areas hit bythe tsunami in Pandeglang, South Lampung, Serang, Tanggamus,Pesawaran regencies, Nugroho said.

Widodo, known as Jokowi, headed to the tsunami affected regionson Monday after ordering authorities to step up relief operations,according to an official statement. The president instructed thepurchase of early warning system equipment by the met agency, knownas BMKG, and to include disaster awareness into schoolcurriculum.

“The tsunami pattern in the Sunda Strait is beyond the BMKGprediction, hence people weren't prepared to rescue themselves,”Jokowi's office said in a statement. Generally, a tsunami will comeafter an earthquake, but this time, “it came without being precededby a quake.”

Surfing haven hit

The tsunami hit Tanjung Lesung, a surfing haven in thewestern-most part of the Java island that's been branded a new Baliby Jokowi's administration. Three to four hours from capitalJakarta, Tanjung Lesung shares its coastline with Ujung KulonNational Park, and is located near factories of state-ownedsteelmaker PT Krakatau Steel and PT Chandra Asri Petrochemical.

Twenty nine people, mostly employees of state-run electricityproducer PT Perusahaan Listrik Negara, were killed when the tsunamiwave swept away the venue of a live music concert attended by about200 people in Tanjung Lesung. The company said 13 people were stillmissing while 157 survived.

No significant damage was reported by companies with majorfactories nearby. Lampung's Panjang Port, the main gate for robustacoffee exports, is operating normally, according to QudratulIkhwan, head of the provincial transportation office. Indonesia isthe world's third-biggest robusta producer.

Indonesia's 17,000 islands are prone to earthquakes because thecountry straddles the Pacific Ring of Fire, an arc of fault linesand volcanoes that causes frequent seismic upheavals. MountKrakatau is about 156 kilometers of west Jakarta and its eruptionin 1883 was one of the deadliest volcanic eruptions in the world,killing more than 36,000 people.

History of disasters

More than 2,000 people were killed and about 80,000 peopledisplaced in Central Sulawesi in September after a devastating earthquake and tsunami struck theisland. That was preceded by a series of deadly earthquakesearly this year that rattled the popular tourist destination ofLombok island, near Bali.

At least 160,000 people were killed on Sumatra island as aresult of a 9.1 magnitude earthquake and tsunami on Boxing Day in2004. More than 1,100 people were killed in another tsunami andearthquake on the same island in 2009.

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