Six people drowned Wednesday after water was discharged from a hydropower station in southwestern China’s Guizhou province, Beijing Youth Daily reported.

The six victims, all villagers from Shuicheng County, were resting in a sport utility vehicle to stay out of the hot afternoon sun when an upriver hydropower station discharged a large amount of water. “The villagers could not escape in time and died,” a local police official told the newspaper.

Authorities have detained the person in charge of the hydropower station, which is privately owned, and are investigating whether the station had notified the public about the discharge in advance.

In a phone interview, the director of Shuicheng County’s publicity department, a man surnamed Li, told Sixth Tone that the six villagers were confirmed dead at the scene, and that the government was negotiating compensation payments with the villagers’ families.

Li could not confirm any details about what happened or whether there had been advance warning. “Several government departments are still looking into the cause of the accident,” he said.

In the laws that regulate hydropower stations, there are no rules for informing people before water discharges during non-flood seasons.

In January 2015, an elderly couple in northwestern China’s Shaanxi province died while trying to cross a river by boat. A hydropower station located downstream had released water without warning, causing the current to become stronger and the boat to capsize.

Editor: Kevin Schoenmakers.

(Header image: Water is discharged from a hydropower station in Panzhihua, Sichuan province, Dec. 1, 2016. VCG)