Mangkhut entered the Philippines as a super typhoon in the early hours of the morning and caused winds and rains throughout the main island of Luzon, home to almost half of the country's 105 million inhabitants.
Known locally as Ompong, Typhoon Mangkhut at one time had maximum gusts of 305 kph (190 mph) before leaving the area before noon and moved to southern China and Vietnam with winds of 170 kph.
Two rescue workers were killed when they tried to free people trapped in a landslide in the mountainous region of Cordillera, said Ricardo Jalad, head of the country's disaster agency. No further details were provided. The police also said that a body had been found in a river in Manila.
The Philippine state meteorological agency, PAGASA, reduced the level of domestic threat, but warned that the danger was far from over, with continuous waves of storms and heavy rains that could trigger floods and more landslides.
"We ask people to stay alert and continue to take precautions," said PAGASA meteorologist Rene Paciente.
Rapid response teams were on alert with the air force for search and rescue missions as authorities carried out damage assessments in areas along the path of the storm, which tore down trees, power poles and ripped up shop signs and sheet metal roofs hundreds of kilometers away.
There were floods in several provinces and parts of the capital, Manila. Authorities were preparing to release water from several dams, fearing that constant rains could push reservoirs to dangerously high levels.
Mangkhut had been a Category 5 storm for days since it wreaked havoc in the Pacific territories of the United States of Micronesia before moving on to the Philippines, where it is the 15th and strongest storm this year.
The typhoon's maximum winds were stronger than those of Hurricane Florence, which killed five people in the United States after it piled up in the Carolinas, knocking down trees and docking rivers and causing major power cuts before degrading to a tropical storm.
Some 105,000 people remained in temporary shelters after the massive evacuation of the coastal areas of the Philippines after warnings of storm surges.
Authorities in some areas of northern Luzon turned off power as a precautionary measure, saying some residents in high-risk areas chose to leave the storm to protect the homes of looters.
More than 1,000 homes were hit in the province of Cagayan, where the storm first made landfall, and authorities in the city of Baggao said they had lost contact with an emergency response team, said Defense Secretary Delfin Lorenzana. .
Rogelio Sending, a government official in Cagayan, said there were power and communication cuts throughout the province and reports of uprooted trees blocking roads.
"This makes cleaning operations really difficult," he said over the phone.
The Philippines remains obsessed with the devastation of Typhoon Haiyan, which killed more than 6,300 people in the central areas of the country in 2013, mostly due to large storm surges.
But authorities say they were better prepared this time in terms of evacuating and informing high-risk communities.
"I talked to the president last night, his clear and concise order to march was to save lives, save lives," said Francis Tolentino, the government's disaster response coordinator and adviser to Philippine President Rodrigo Duterte.
Renato Solidum, a senior official in the Department of Science and Technology, said people in northern Luzon suffered a super typhoon in 2016 and were not taken by surprise.
"There has been a dissemination of aggressive information to prepare well," he said.
"Because people had experienced a super typhoon recently, they really had imagination about what happened before and they really need to be prepared."