The dead bodies of two brothers and one of their wives have been found in an empty water tank in NSW Southern Tablelands. According to the police, an invisible and odorless gas is to be blamed for their deaths.

One of the victims, a 69-year-old man, was doing maintenance work in an empty, in-ground cement water tank located on the farm near Gunning in the Southern Tablelands on Thursday. According to SW Police Superintendent Andrew Koutsoufis, there was a petrol pump being used to clean the tank and it could have build up fumes at the bottom of it, causing carbon monoxide poisoning.

The man’s brother, aged 68 years, went to the tank to check up on him and he also suffered the same fate as his brother. Then, the 63-year-old wife of the 69-year-old man saw the pair and alerted a neighbor before going into the tank, trying to rescue them both. But she also died in her attempt.

A neighbor found the trio’s bodies after 6 PM. Emergency services were called and rushed to the scene. The police said that it was a tragic incident. The trio’s bodies remained in the tank overnight while the authorities waited for the accumulation of the gas to clear up. According to the Daily Telegraph, another man and women also collapsed when they tried to help them.

Normally, carbon dioxide is present in the atmosphere and is essential to life on Earth. On the other hand, when it is present in very high concentrations, this gas can be very dangerous. A pump or a motor can generate the gas, which passes through the equipment’s exhaust. This causes the concentration of carbon dioxide to increase in the surrounding air.

Once the gas leaks, it accumulates on the floor once you have a pump or a motor working. But no one can notice as it builds up.

“Carbon dioxide is a silent killer, you can’t see it, you can’t smell it, you don’t know it’s there. If you saw your wife in the bottom of a water tank passed, out, you think I will go and get her out,” a local agricultural supplier told The Daily Telegraph during an interview. “If you imagine a water tank, that is not an easy task at the best of times, that’s a very hard to do, the time frame is a little while, to actually try and get them out.”

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