Super Typhoon Ragasa, the world's largest tropical storm this year, killed at least 17 people in Taiwan and claimed 10 more lives in the Philippines on Wednesday.
The deaths in Taiwan were caused after a mountain barrier lake overflowed into nearby communities due to heavy rains, authorities said.
The Central Emergency Operation Center (CEOC) said the lake, formed in Hualien County after an earlier typhoon in July, spilled over Tuesday, flooding surrounding areas.
Authorities said that, in the affected zones, at least 17 residents were still missing.
More than 8,000 villagers had been evacuated earlier in the week as Typhoon Ragasa approached Monday.
Television footage showed the surge destroying at least one bridge, with residents climbing onto vehicles and buildings to await rescue as the lake's dark, muddy waters swept through Guangfu Township. Roads were destroyed by the flood and railway lines were submerged.
Officials reported that approximately 15.4 million tons of water – equivalent to about 6,000 Olympic-sized swimming pools – surged out of the lake, carrying water mixed with large amounts of sand and sediment.
Across the island of Taiwan, at least 32 people were injured in typhoon-related incidents, authorities said.
The rescue efforts continued in Hualien on Wednesday. But roads remained clogged with thick layers of mud, making the operations difficult, and many vehicles were stuck in the sludge, images from the scene showed.
Most of the deceased were elderly residents with limited mobility who lived at home in Guangfu Township.
Taiwan's EBC News reported that an elderly woman stood on a street covered in muddy sludge, crying as she said her 87-year-old mother did not have time to escape and drowned trapped inside her home. "Her body is still there, buried under the mud," she said.
Premier Cho Jung-tai visited disaster-hit areas in Hualien to inspect bridge damage and oversee relief operations.
"For those who tragically lost their lives, we need to find out why a full evacuation wasn't carried out in the areas affected," Cho said.
Officials said on Wednesday that the barrier lake's overflow has gradually eased as rainfall diminished, with its water volume reduced by 75% since the surge.
President Lai Ching-te said Wednesday that the military has established a command post in Guangfu Township, deploying around 5,000 personnel and over 100 vehicles and machines to support disaster relief operations.
"The top priorities now are locating missing residents, rescuing those trapped, and strengthening local communications," Lai said in a Facebook post.
In the Philippines, Super Typhoon Ragasa claimed 10 lives, with 13 injured, police and government officials said Wednesday, as the weather bureau warned of a new storm threatening the eastern region.
About 192,000 people were affected, including nearly 25,000 who were displaced, according to the national disaster agency.
The fatalities included seven fishermen whose boat capsized off the northern province of Cagayan, which bore the brunt of Ragasa's onslaught, the coast guard said. Previously, four were reported dead and three more missing.
The fishing boat docked at a pier in Sta Ana to seek shelter from Ragasa, but the crew did not leave the boat, so some of them were trapped underneath the ill-fated vessel.
The other fatalities were found floating in nearby mangroves, the coast guard said.
In Benguet province, one person died and seven were injured when landslides struck vehicles on a highway in Tuba town, the disaster agency said.
A village security officer died when he was hit by a fallen tree branch in Calayan town in Cagayan, while a 67-year-old man died after he slipped and fell into a river in La Union province, according to police and the coast guard.
The weather bureau said Ragasa, locally called Nando, maintained its strength as it exited the Philippines, packing maximum sustained winds of 185 kph and gusts of up to 230 kph while moving towards southern China.
As Ragasa moved out of the Philippines' area, a new tropical storm was approaching the country and expected to bring rain by Thursday, the weather bureau said.
Tropical Storm Bualoi, locally called Opong, was intensifying as it churned towards the Philippines' eastern provinces, with maximum sustained winds of 85 kph and gusts of up to 105 kph.
"Opong will continue to intensify while over the Philippine Sea and may reach typhoon category before making landfall over Bicol Region," the weather bureau said.
"It will then weaken as it crosses the archipelago, although it will likely remain as a typhoon or severe tropical storm during the passage," it added.
Typhoon Ragasa passed near Taiwan and the Philippines between Tuesday and Wednesday. It is expected to make landfall in southern China later on Wednesday with the second-highest typhoon category.
Meteorologists expect it to weaken as it moves along its projected path to the west.
