Super Typhoon Koppu made landfall early Sunday in the Philippines, toppling trees, knocking out power and communications, and destroying homes.

Forecasters feared the storm could pound parts of the country with as much as 6 feet of rain and cause catastrophic flooding. There were no reports of casualties.

Typhoon Koppu, known as “Lando” in the Philippines, reached Casiguran in Luzon’s Aurora province at 1 a.m. local time Sunday morning (1 p.m. Saturday ET). There were reports of power outages and even before the storm hit, its outer bands drenched the country’s east coast with heavy rains.

The typhoon was moving west at 3 kph (1.8 mph) Sunday morning, according to the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA). The slow movement caused fears that the damage could be greater as the storm lingers.

“It has slowed almost to a crawl. We’re hoping it would speed up and spare us sooner,” Alexander Pama, who heads the government’s main disaster agency that has overseen evacuation and pre-deployment of rescue contingents, told The Associated Press.

“Initially, we are getting many houses were destroyed, power lines toppled and trees blocking major roads,” he told Reuters, adding 10,000 people had been displaced in northeastern Luzon, the country’s main island.

The U.S. military’s Joint Typhoon Warning Center upgraded Koppu to a super typhoon — a term for typhoons with maximum winds of at least 150 mph, the equivalent of a Category 4 hurricane — on Saturday. Koppu is the strongest typhoon to make landfall in Luzon in five years, The Weather Channel reported.

Residents in Aurora, the city of Santiago and the province of Quirino had already reported power outages Sunday morning, according to the Philippine Red Cross.

The Philippines Department of Education announced that classes would be canceled in five cities and provinces on Monday, and warned families to prepare emergency kits and heed evacuation orders.

Communities that are prone to flash flooding were under “force evacuation” orders, while some villagers voluntarily moved to safer ground, according to The Associated Press.

Related: Typhoon Koppu Strengthens, Edges Closer to Philippines

The biggest threat from the typhoon was expected to be its “catastrophic flood threat” from a multi-day deluge, the Weather Channel said.

Weather Channel senior digital meteorologist Nick Wiltgen predicted “prolific rainfall as it grinds across the mountains and valleys of Luzon … [which is] home to almost half of the country’s 98 million people.” Luzon could receive up to six days of heavy rainfall, he added, with 20 to 40 inches of rain possible.

In certain areas, depending on the track of the storm, nearly 80 inches “would not be unrealistic,” Wiltgen said. Meanwhile, in the densely populated metro Manila area, home to some 12 million residents, more than a foot of rain could fall, triggering flash flooding.

The Philippine weather agency PAGASA warned Koppu’s eyewall could cause heavy damage to structures and crops. PAGASA said the storm was delivering winds of more than 100 mph in Aurora early Sunday morning local time.

Nearly 1,900,000 impoverished families could be affected by the typhoon, according to the Philippines Department of Social Welfare and Development, which said $226,146 had been made available for emergency assistance.

On Friday, President Benigno Aquino III, in a nationally televised address, warned that about 7.5 million people would likely need help during and after the storm. It was the first time since Typhoon Haiyan hit the country, leaving more than 7,300 people dead and missing, that he had issued a national storm warning.