Photo/IllutrationPolice examine the carbonated water well where two people drowned in Kaneyama, Fukushima Prefecture, on Aug. 15. (Motoyuki Tanaka)

  • Photo/Illustraion

KANEYAMA, Fukushima Prefecture--An elderly man and his niece fell into a famed local well here on Aug. 15 and drowned, after possibly being rendered unconscious by the low oxygen levels around the natural carbonated water source.

Isao Morohashi, 77, of Nagaoka, Niigata Prefecture, and his niece Ruriko Isa, 49, who lived in the same city and was a company employee, fell into the well around 5:10 a.m.

They were visiting the well to collect the natural sparkling water emanating from a spring, which is bottled locally and even served at prominent gatherings of world leaders.

Fukushima prefectural police, who are investigating the accident, believe that low oxygen levels around the water surface because of the carbon dioxide might have made them lose consciousness.

According to police, the two traveled to the site by car along with three other relatives. Morohashi and Isa went out to collect the natural sparkling water, but did not return.

When the relatives went to the well, they found them inside.

According to the fire department, they were in cardiac and respiratory arrest and they did not have any severe injuries when they were discovered.

The depth of the well is about four meters and the water level was at about a height of three meters. The opening of the well is located at ground level.

There are no fences around the well, but the opening is covered with nets to prevent people from falling in. However, part of the nets were lifted up at the time of the accident.

According to a city official, the well has long been a famed source of carbonated water.

Residents and tourists can collect the water freely, and dealers also collect it and sell it in plastic bottles.

Bottles of the sparkling water were served at the Ise-Shima G-7 summit in 2016 and the recent G-20 Summit in Osaka.

(This article was written by Masahito Iinuma and Morikazu Kogen.)