MANILA, Philippines -- The first major typhoon of the monsoon season slammed into the northern Philippines early Saturday, leaving at least one person dead and sending rivers of volcanic ash through towns near Mount Pinatubo volcano.
Typhoon Koryn hit the northeast coast of the main Philippine island of Luzon before dawn Saturday, packing peak winds of 112 mph.
The government weather service said Koryn was moving west-northwest at 16 mph and would push into the South China Sea by early Sunday.
The service downgraded storm warnings across Luzon, but officials said typhoon-induced flooding would remain a threat.
The Disaster Coordinating Council reported one person was electrocuted during the storm in Ilocos Sur province, 170 miles north of Manila.
Several major highways in Manila were flooded, stranding commuters and forcing businesses to close.
Strong rains brought by Koryn touched off secondary explosions on the northeastern slope of Mount Pinatubo, spewing ash clouds up to 900 feet.
The government earlier warned that Koryn's rains could unleash devastating torrents of volcanic ash and mud down Pinatubo's slopes. The peak deposited several tons of debris on its flanks when it erupted in June 1991.
The Philippine Institute of Volcanology and Seismology described as 'moderate' the flow of the material, called lahar, at mid-day Saturday.
'There might be some major lahar events if the rains are sustained,' institute spokesman Jason Villegas said. 'But it is our understanding that the rains around Mount Pinatubo were not as heavy as they were in other places like Manila.'
Officials in Tarlac province just north of Pinatubo reported lahar flowing about 3 feet deep through at least one low-lying area, forcing the evacuation of some 1,200 people.
Cascading ash and mud from the volcano, 55 miles northwest of Manila, buried towns and lay waste to once fertile farm land during the country's rainy season last year.
