27-year-old Ukrainian chess champion Stanislav Bogdanovich and his 18-year old girlfriend, Alexandra Vernigora, also a top chess player, were found dead in their Moscow apartment from an apparent accident involving nitrous oxide, or ‘laughing gas’ as it is commonly known.

Media reports indicate the couple was found with balloons, which are often used to inhale the gas, and a source told Interfax that the heads of both victims were in plastic bags. A gas canister was also found next to their bed, according to reporting from RT.

Oxygen deprivation resulting in a loss of blood pressure, fainting and even heart attacks is a key risk associated with recreational use of nitrous oxide. Users that engage in excessive breath-holding or any other means to cut off a supply of fresh air are especially prone to a risk of fatality.

Bogdanovich sparked outrage in his home country after deciding recently to represent Russia in an internet chess match against Ukraine. In a Facebook post, he explained his decision. “I answer those who do not understand why I played for Russia. First of all, I’m grounded for this. I only do what is best for the business. While there were no donations, I honestly did not play for anyone. Secondly, I am now in Russia. It would be ugly, as a guest, to oppose those who provide a warm welcome. This is just a tribute.”

Young chess star couple are found dead after laughing gas overdose https://t.co/3U7NqqsN6J via @MailOnline — Beth (@LRislandGirl) March 6, 2020