When they returned to their home near the beach, there was nothing left.

“It wiped out my house and all the things in it,” he said.

At least 429 people died and nearly 1,500 were injured in the Sunda Strait tsunami, which struck western Java and southern Sumatra. The number of casualties was high in part because many people were at the beach enjoying a long holiday weekend.

But officials acknowledge that many lives could have been saved if the country had an adequate tsunami warning system.

Even with its flaws, the existing system can detect tsunamis caused by seismic activity. But the system is not set up to detect tsunamis caused by volcanic activity, even though the threat is well understood by scientists and the technology for detecting them exists.

“The disaster early warning system in Indonesia is still far from satisfactory,” Mr. Sutopo said.

Officials initially said the Sunda Strait tsunami was three feet high, an estimate they later raised to 10 feet. Mr. Sutopo said Tuesday it was even higher, reaching more than 16 feet in some areas.

One of those places was Sumur, the area that includes Mr. Damin’s fishing village of Sumber Jaya. Nearly all of the houses in the village were damaged or destroyed.

Members of the public were warned Monday to stay away from the coast of the Sunda Strait for at least two days for fear that Anak Krakatau — the Child of Krakatau — could set off another tsunami.