Seven people, including four children, died at the bottom of a well in Siem Reap province on Saturday evening in a tragic sequence of events that started with the father of a poor family dropping 3,000 riel and a cigarette lighter into the five-metre-deep shaft.

When his children heard what had happened, they tried to retrieve the money. One passed out and died at the bottom of the well due to a lack of oxygen. Two more children, each trying to help, also climbed down and suffered the same fate.

Four more neighbours, including a 12-year-old, each went down to help the children. None came back up.

The nightmarish episode began on Saturday morning, as Tuy Chin, 50, of Banteay Srey district’s Romchek commune, was collecting water from his family’s well.

He dropped the 3,000 riel (about $0.75) and his lighter, and went down to collect them, said Muy Norn, the district’s acting police chief.

“He put the ladder into the well and climbed down to get his lighter. But he could not find the money so he climbed back out without removing the ladder.”

After returning home, Chin happened to mention to his teenage daughter that he had lost the money in the well, not thinking that his children would try to retrieve it.

But in the late afternoon, Chin’s 11-year-old son climbed down into the well. His 13-year-old sister then climbed down to find her brother but the same happened to her. A 15-year-old sister then followed. All died.

Police and local health officials believe the low level of oxygen in the well shaft is what caused the deaths.

“These three kids are siblings, and when their neighbours heard about the kids lost in the well, they also climbed down to help. But the four people who tried to help, they also died one after the other in the same well,” Norn said.

“An eighth person who went down to help survived in a serious condition, but he was sent to hospital to receive help on time.”

The concrete well was dug more than 10 years ago and is irregularly used because it doesn’t provide much water, according to police.

The bodies were retrieved by local authorities and villagers by using a rope, Norn said, with the process taking several hours as the rope had to be hooked around the bodies one by one and hauled out.

According to scientists, at oxygen levels between four and six per cent, humans fall into a coma within 40 seconds, followed by convulsions before respiration ceases. Oxygen levels above ground are normally about 21 per cent.

“The health officials said that the well has less oxygen in the evening, which is what caused those seven people to die. But it has more oxygen in the morning, and that’s why the children’s father was fine when he went down,” Norn said.

Che Chhan, 30, a sister of the three siblings who died in the well, yesterday blamed her family’s poverty for the tragedy.

“My 11-year-old brother knew that my father had lost 3,000 riel in the well and he wanted to get it back, without thinking it would be dangerous. And now so many people have died like this.

“I wanted to blame my father, because if he did not tell them about the money, they would not have died. But it’s over now. They would not come back if I blamed my father… but the villagers blame my father and say he was careless.”

The seven victims were to be cremated last night, and the family – which had 13 children before Saturday’s tragedy – will destroy the well, she said.

The seven dead are Che Oun, 11; Che Chea, 13; Chea Ratana, 15; Hay Chandy, 12; Hay Sangda, 22; Peat Poung, 35; and Toy Team, 27.