MANILA, Philippines – Flash floods devastated a southern Philippines region unaccustomed to serious storms, killing more than 400 people while they slept, rousting hundreds of others to their rooftops and turning two coastal cities into muddy, debris-filled waterways that were strewn Saturday with overturned vehicles and toppled trees.

Most of the victims were asleep Friday night when raging floodwaters cascaded from the mountains after 12 hours of rain from a late-season tropical storm in the southern Mindanao region. The region is unaccustomed to the typhoons that are common elsewhere in the nation of islands.

Ayi Hernandez, a former congressman, said he and his family were resting in their home in Cagayan de Oro late Friday when they heard a loud “swooshing sound” and water quickly rose ankle-deep inside. He decided to evacuate to a neighbor’s two-story house.

“It was a good thing, because in less than an hour the water rose to about 11 feet,” filling his home up to the ceiling, he said.

At least 436 were dead, based on a body count in funeral parlors, Philippine Red Cross Secretary General Gwen Pang told The Associated Press. She said that 215 died in Cagayan de Oro — a city of more than 500,000 — and 144 in nearby Iligan, with more than 300,000 residents. The rest died in several other southern and central provinces, she said.

Many of the bodies were unclaimed after nearly 24 hours, suggesting that entire families had died, Pang said.

The number of missing was unclear Saturday night. Before the latest Red Cross figures, military spokesman Lt. Col. Randolph Cabangbang said about 250 people were still unaccounted for in Iligan.

The swollen river sent floodwaters gushing through neighborhoods that do not usually experience flooding. A man floated in an inner tube in muddy water littered with plastic buckets, pieces of wood and other debris. Ten people in one home stood on a sloping roof, waiting for rescuers even as water still flooded the lower floors.

Local television footage showed muddy water rushing in the streets, sweeping away all sorts of debris. Thick layers of mud coated streets where the waters had subsided. One car was thrown over a concrete fence and others were crushed and piled in a flooded canal.