By Jessie Yeung, Wayne Chang, Laura Sharman, CNN

Hong Kong (CNN) — Nearly 2 million people in southern China were evacuated as a powerful typhoon hurtled into one of the world’s most densely populated coasts, having already unleashed deadly flooding in Taiwan.

Ragasa brought finance hub Hong Kong and swathes of southern China to a standstill on Wednesday, after barreling through remote islands in the Philippines and mountainous regions of Taiwan.

It began to lose strength and was downgraded to a severe tropical storm in the early hours of Thursday morning, local time, but not before leaving a trail of damage – triggering landslides, flooding and huge waves in China’s Guangdong province, home to massive cities like Shenzhen and Guangzhou.

With the storm expected to keep moving westward on Thursday, some train services in southern China have been suspended, while the country’s central government has earmarked around $49 million for relief efforts, according to state media.

Schools, factories and transport services were initially shut down in about a dozen cities, but some distant from the landfall location prepared to resume work as winds weakened.

In Taiwan, at least 14 people died and 31 others were still missing Thursday after a natural dam holding back a recently formed lake collapsed a day earlier, unleashing 68 million tons of water and flooding the nearby Guangfu township. Officials had revised the death toll down on Thursday, saying there had been some double-counting in earlier numbers provided.

Videos from the town, in the mountainous eastern Hualien county, show a torrent of water rushing through the streets, with cars swept away and residents sheltering on higher floors as the lower levels of their homes become inundated.

Debris from a landslide in July had formed the natural dam, and authorities had been warning for weeks the remote lake could overflow by October. At a news conference on Wednesday, officials said assessments showed it wasn’t feasible to dredge, siphon or otherwise remove the dam barrier – so they opted to monitor the situation instead.

Before Ragasa hit, authorities said they had issued multiple warnings and evacuation advisories to residents who could be impacted if the lake overflowed.

A large bridge in Hualien was also washed away by the rush of water following the collapse of the natural dam.

Ragasa is expected to continue to deteriorate over China, bringing heavy rain, and ultimately dissipate over Vietnam on Friday.

Southern China battered

The Philippines, Taiwan and southern China experience multiple typhoons annually, but the human-caused climate crisis has made storms more unpredictable and extreme.

Illustrating this new reality, videos circulating on Chinese social media showed uprooted trees and shattered windows in Yangjiang, where Ragasa made landfall on Wednesday afternoon with the equivalent strength of a Category 3 hurricane.

Further footage showed severe flooding in Zhuhai, a coastal city neighboring Macao.

Residents of seaside high-rises were ordered to evacuate on Tuesday afternoon, according to state media, with many taking refuge with relatives, checking in to hotels or moving to temporary government shelters like school gyms.

One longtime resident, who relocated with her family to a school gymnasium, told local outlet Hongxing News it was the first time in her three decades living in Zhuhai that she had ever been evacuated.

A further 1.89 million people were evacuated from China’s southern Guangdong province by Tuesday night, ahead of the storm’s arrival, according to the provincial emergency management department.

As the storm approached the international finance hub of Hong Kong early Wednesday, it brought lashing winds that felled trees and ripped scaffolding off buildings.

Video circulating on social media showed storm surges shattering the glass doors of the Fullerton Ocean Park Hotel, a luxury seaside resort, with huge waves gushing into the lobby and sweeping people off their feet.

In a statement to CNN, the hotel said no injuries were reported and that the government had “immediately” mobilized resources to respond.

Photos and video from Macao showed waist-deep water flooding the streets of the tourism and gambling hub, often dubbed the most densely populated city on earth.

Footage from Shenzhen, just across the border from Hong Kong, showed massive waves crashing into a coastal park Tuesday night, with winds reaching 181.44 kilometers per hour (112.4 mph).

Strong track record of preparing for typhoons

Though southern China is highly populated, with tens of millions potentially impacted by the storm, it’s also well prepared.

Here, cities are frequently in storm paths and have developed sophisticated infrastructure to combat weather-related dangers – including a vast $3.8 billion drainage network that has saved Hong Kong from floods that decades ago routinely cost lives and caused widespread destruction.

This year has been particularly stormy. Hong Kong typically experiences about six typhoons annually, but Ragasa marks the ninth typhoon so far this year, according to the City University of Hong Kong.

Climate change is making storms of this scale not only more common but more powerful too, according to Johnny Chan, an atmospheric scientist at the Asia-Pacific Typhoon Collaborative Research Centre.

“Because of global warming, you will have more moisture in the atmosphere and (the) water temperature is also high, therefore … once the storm develops, it has more energy,” said Chan.

He warned cities in Asia would need to continually update their building codes to handle stronger winds, higher sea levels and more intense typhoons.

“Most of the building codes were designed based on the past data, but the past data would not be accurate anymore for the future,” he said.

Cleanup efforts are now underway in the Philippines, where the typhoon had been the equivalent of a Category 5 hurricane when it struck northern parts of the country on Monday.

At least seven fishermen were killed after a boat overturned off the coast off Luzon on Monday, according to the state-run Philippine Information Agency.

Another storm, called Opong, is now intensifying in the Philippines in the aftermath of Ragasa, and typhoon season still has many months left.