Former Washington Capitals defenseman Alexei Tezikov died of a heart attack on July 16. According to BestSportNews, Tezikov became ill on the streets, and could not regain consciousness before the arrival of an ambulance. He was 42.
Former @Capitals and @Canucks player Alexei Tezikov, 42, suddenly passed away on July 16. Tezikov felt ill on the street, and died before the arrival of the ambulance crew, without regaining consciousness. @hc_lada https://t.co/qXXtZhM4U9
— Eurohockey com (@eurohockey) July 17, 2020
Tezikov was born on June 22, 1978 in Togliatti, Russia. The Buffalo Sabres drafted him in the 1996 NHL Entry Draft in the fifth round with pick #115 overall.

Russian professional ice hockey player Alexei Tezikov of the Washington Capitals skates on the ice during a game, October 1999. (Photo by Len Redkoles/BBS/Getty Images)
The Caps acquired Tezikov from Buffalo on March 23, 1999, the trade deadline, in exchange for Center Joe Juneau. Draft picks were also exchanged, with the Sabres acquiring a third round pick for 1999 and the Caps acquiring a fourth round pick for 2000.
The AHL is saddened to learn that former All-Star defenseman Alexei Tezikov passed away Thursday at the age of 42. Tezikov played 183 games in the AHL with @AmerksHockey, Portland, Cincinnati and the @ManitobaMoose between 1998 and 2002. pic.twitter.com/OoaNbslMoG
— AHL Communications (@AHLPR) July 17, 2020
Tezikov played during the 1998-99 and 1999-00 seasons for the Capitals, playing five games during the 98-99 season and 23 games during the 99-00 season.
During his career with the Capitals, Tezikov scored one goal and recorded one assist during the 1999-00 season. His time in the Capitals organization was primarily spent with their AHL farm team, the Portland Pirates.

Russian professional ice hockey player Alexei Tezikov of the Washington Capitals skates on the ice during a road game, 1999-2000 season. (Photo by Jim McIsaac/BBS/Getty Images)
In addition to playing with the Caps, he also played in two NHL games with the Vancouver Canucks in 2001-02.
Tezikov left North America after that and played with various teams, primarily in the Russian Super League (RSL) and the Kontinental Hockey League (KHL).
Here is link to writeup of his death from the junior team he played for, the Moncton Wildcats.
Further Reading
The Russian Influence in Washington: The History of Russians on the Washington Capitals
By Diane Doyle