ILIGAN, Philippines – As a storm that killed more than 650 in the southern Philippines raged outside the store where she works, Amor Limbago called home to check on her parents, but their cellphones just kept ringing and later went dead.

Limbago, 21, rushed home as soon as the flash floods receded and confirmed her worst fear: Her parents and seven other relatives were gone, swept away from their hut by the river. They had eagerly planned a small Christmas dinner in that hut just days earlier.

Tropical Storm Washi blew away Sunday after devastating a wide swath of the mountainous region on Mindanao island, which is unaccustomed to major storms. It killed at least 652 people and left more than 900 others missing, the Philippine Red Cross said.

Most of the victims were asleep Friday night when flash floods cascaded down mountain slopes with logs and uprooted trees, swelling rivers. The late-season tropical storm turned the worst-hit coastal cities of Cagayan de Oro and nearby Iligan into muddy wastelands.

Most of the dead were children and women, Red Cross Secretary General Gwendolyn Pang said. In just 12 hours, Washi dumped more than a month of average rain on Mindanao.

Thousands of soldiers, polices and civilian volunteers were mobilized for rescue efforts. Rescuers in boats rushed offshore to save people swept out to sea.