I remember seeing KINISKI in two NWA title matches, both at the original Charlotte Coliseum. One was against Tex McKenzie, the other against Rip Hawk.
 
He was a very intimidating person to the fans and a great champ.

Here is the information from Wrestling Observer:
 
Gene "Big Thunder" Kiniski, one of the great pro wrestlers of all-time, passed away this morning at his home in Blaine, WA.  Kiniski, 81, had been battling cancer for some time and his death was not a surprise.
 
Kiniski, a former college football player at Arizona, was a headliner from almost the start of his career in 1953.  He made his name as a top heel in Canada through the nationally televised events in the 50s with a legendary feud with Whipper Billy Watson, the biggest star at the time in Canadian wrestling.  He was also in the mix with names like Killer Kowalski, Yvon Robert and Edouard Carpentier when pro wrestling's popularity peaked in Montreal during the late 50s.
 
During his career he held the Montreal version of the world title, the AWA world title, the WWA world title and had his big run from January 7, 1966 through February 11, 1969, when he held the NWA world title.  He was generally regarded as one of the best workers in the business during the 50s and 60s.  He also had ownership in the Vancouver wrestling promotion until 1983.  During the 60s and through the mid-70s, British Columbia had a strong local promotion featuring some of the best wrestlers of that era.
 
Two of his sons, Nick and Kelly, became pro wrestlers in the 80s.
 
Kiniski headlined a number of baseball stadium shows in many different parts of the world during his career, most notably a Montreal world title match with Kowalski, an NWA title match with Fritz Von Erich and an International title match at the old Budokan Stadium in Tokyo against Giant Baba, which is often considered the greatest match of Baba's career.