Updated at 10:55 p.m. ETTyphoon Mangkhut has ripped through the Philippines, causing swift damage and at least 12 deaths. The over-525-mile-wide storm is now heading for Hong Kong.As NPR's Julie McCarthy reports, the storm knocked out power, cut telephone lines, and triggered landslides and storm surges. But, she said, "A thorough assessment of the damage is all but impossible because of all the inclement weather this storm has pulled in its wake." Residents in Hong Kong woke up on Sunday morning to warnings of the approaching storm. The federal Hong Kong Observatory upgraded the storm's rating to a Number 10, indicating that residents should expect wind speeds at hurricane levels or faster. The storm is expected to make landfall south of Hong Kong around midday Sunday. Officials expect water levels to rise in Hong Kong's Victoria Harbor and are warning residents to take shelter. At about 4 a.m. local time Sunday morning, the Joint Typhoon Warning Center of the U.S. Navy measured the storm's sustained winds at just above 100 mph as it headed towards Hong Kong. The center forecasts maximum sustained winds at just over 90 mph through Sunday; wind speeds are predicted to dissipate as the storm continues moving over land. Impact on the Philippines Formerly classified as a super typhoon, Mangkhut is known as Ompong in the Philippines — asMcCarthy reports, the government gives it a "Filipino cast" to engage the public. The ferocious storm arrived in the Philippines at around 1:30 a.m. local time on Saturday, with sustained winds of over 120 mph. It was downgraded to the equivalent of a Category 4 hurricane after it made landfall, according to the Associated Press.It struck northern Luzon, the biggest island in the Philippines, a terrain home to over half of the country's population featuring both mountains and farmland. As rain fell non-stop for hours, the country's rice-producing region was flooded. The Red Cross predictedbefore Mangkhut's landfall that it will destroy 1 million tons of rice. Reuters reports 42 landslides throughout the country — some deadly.Francis Tolentino, an adviser to Philippine President Rodrigo Duterte, spoke from the disaster zone on Saturday evening, local time,according to the Associated Press. He said at least 12 were dead in the northern Philippines, including an infant, and that the toll could climb as reports are investigated. The National Defense Office has confirmed two deaths to NPR: Two rescuers were killed in a landslide in a mountainous region. The agency is also investigating more reports, including three more who have allegedly died in a separate landslide and four cases of missing persons.Historically, typhoons of this magnitude generate hundreds, sometimes thousands of deaths. Super Typhoon Haiyan — a more powerful storm than Mangkhut — killed more than 6,000 people in the Philippines in 2013. Officials were worried that Mangkhut could be just as catastrophic. "We really learned a lot from the Haiyan experience," Catherine Cabarles, a school teacher in Quezon City, told NPR before Mangkhut arrived. "After that Haiyan experience ... many of us are evacuating to higher places." Before the storm made landfall, Civil Defense used that knowledge to pre-position hundreds of thousands of food packs. Police were deployed near the impact zone to prevent looting, and armed forces prepared to take the lead on search and rescues. More than 4 million people were declared at risk from the storm, and around 87,000 evacuated, with 105,000 are staying in temporary shelters, according to Reuters. Communication is cut from many areas and high winds are preventing responders, meaning it's too early for a full assessment of damage. "In a storm this intense it's difficult to imagine that more damage isn't out there," NPR's McCarthy said. "The poor families living in [the Northern Philippines] have less capacity to recover quickly," Jerome Balinton, a Humanitarian Response Officer with Save the Children in Santiago City, told NPR. "They are not well-equipped to immediately cover, for example, the need for shelter repair, the need to replace their household essentials." "The schools will definitely be affected," Balinton said. "If these schools or communities don't have enough capacity to immediately repair their school infrastructure or replace the teaching and learning materials, surely the typhoon will cause a long-term impact to children's access to education." Now, Hong Kong is bracing for the storm's impact: Many businesses and homes are shuttered, nuclear power plants in the storm's path are "in combat readiness" and hundreds of flights from the Hong Kong International Airport have been cancelled, according to the South China Morning Post. The Post also reports Hong Kong's Civil Aid Service has deployed staff to "help residents take precautions" and appeal to those in the most risky areas to evacuate. Copyright 2018 NPR. To see more, visit http://www.npr.org/.