Despite government warnings, Mr. Mendoza and a few other residents of the island ventured back from emergency shelters on Tuesday to see firsthand what remained of their homes, and perhaps salvage a few belongings. A reporter and photographer from The New York Times accompanied them.

Among the first challenges they faced as they sloshed ashore from a motorized canoe was the two feet of ash. It was difficult to see precisely where the water ended and the land began. Hundreds of dead, ash-coated tilapia bobbed in the gentle current, injecting the smell of rotting fish into the sulfur-scented air.

In some places, rain had already hardened the ash, like crusty snow, making it relatively easy to walk over. Elsewhere, the ash was still soft and treacherous.

Mr. Mendoza choked back tears as he salvaged a plank of wood from what had been his house.

“We had happy memories here,” he said. “The island sustained our livelihoods, but also took everything back. Everything’s gone in the blink of an eye.”

Coconut trees are now blackened stumps, and the menacing mountain was still belching plumes of smoke and ash with ultrafine particles that are dangerous to breathe.