KONTAN.CO.ID - PENANGGAL, Indonesia. In the wake of the deadly Semeru eruption on Indonesia's Java island, the entwined bodies of a mother and daughter encased in molten ash have come to symbolise what many living in the shadow of the volcano feel went wrong.

"There was no warning. If there had been, there wouldn't have been victims, right?" said Minah, of her cousin Rumini, who died clutching her elderly mother as their kitchen roof caved in. Like many Indonesians, they use only one name.

Nestled at the base of volcano, their village of Curah Kobokan was among the worst-hit when Semeru spectacularly erupted on Saturday, ejecting ash clouds and pyroclastic flows that killed 43 people and left dozens missing.

The eruption of Java's tallest mountain has raised questions about the effectiveness of Indonesia's disaster warning system, and the dangers of rebuilding on the volcano's fertile but precarious slopes.

Officials said some messages were sent to local administrators but acknowledged they did not result in an evacuation order, in part because the volcano's activity is hard to predict.

Warnings to evacuate are normally relayed by the national disaster mitigation agency, such as in 2017 when it ordered 100,000 people living near Bali's rumbling Mt Agung to immediately leave the danger zone.

The national disaster mitigation agency did not immediately respond to Reuters' request for a comment.

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In Javanese, the village's name Curah Kobokan means "pouring bowl", a reference to the river that snakes by it. Once a source of life, the river would also become the community's downfall.

When Semeru erupted, the river carried thick flows of lava and ash directly into Curah Kobokan, now a field of gray ash piled as high as the powerlines, a few triangular roofs jutting out of the newly formed disaster landscape.

Residents say the air grew blazing hot and pitch black in seconds. People screamed and fled in panic, some taking refuge in a prayer house, others huddled in a concrete drain.

Of eight residents Reuters interviewed, not one said they received warning of an impending eruption.

"If there had been warning, people would have evacuated. Instead in a matter of minutes, lava streamed down and a lot of people died," said 41-year-old Irawati, whose husband was knocked unconscious as they tried to escape.

Editor: Yudho Winarto