Fredd Young, the hard-hitting linebacker who helped define the Seattle Seahawks of the mid-1980s, has died. He was 64.

New Mexico State Athletics confirmed the news Wednesday. A cause of death was not immediately released.

Young spent only four seasons in Seattle, from 1984 through 1987, but he left a mark that still shows up whenever the franchise looks back on its first half-century. The Seahawks later named him to their 35th Anniversary Team and included him among the Top 50 players in team history.

Seattle selected Young in the third round of the 1984 draft, 76th overall, out of New Mexico State. The Dallas native arrived as a special-teams terror before becoming a fixture at inside linebacker.

As a rookie he became the first AFC player who was not a return specialist to earn a Pro Bowl berth solely for special-teams work. He blocked two punts in a Seahawks uniform, a total that remains tied for second in franchise history.

One play from that first season stayed in highlight reels for years. On a Monday night at the Kingdome, Young leveled Raiders returner Dokie Williams on a kickoff during a 17-14 win over the defending Super Bowl champions.

“Fredd Young was just a great special-teams player,” Tom Flores, then the Raiders’ coach and later the Seahawks’ head coach from 1992 to 1994, once told The Seattle Times.

That 1984 club finished 12-4, the best record in franchise history until the 2005 team went 13-3. Special teams under Chuck Knox and coordinator Rusty Tillman were a big reason why.

Young moved into the starting lineup in 1985 and led the Seahawks in tackles three straight years: 118 in 1985, 121 in 1986 and 101 in 1987.

His finest season came in 1987. In 13 games he recorded nine sacks, forced five fumbles and returned an interception 50 yards for a touchdown in a 35-13 victory at the Los Angeles Raiders. He was named a first-team All-Pro and finished third in Associated Press Defensive Player of the Year voting.

Young made the Pro Bowl in each of his four Seattle seasons — twice as a special-teamer and twice as a linebacker. Those four selections are tied for eighth in team history with Richard Sherman, Marshawn Lynch and Kam Chancellor. He is one of only 10 Seahawks defensive players to earn first-team All-Pro honors.

A contract dispute followed the 1987 season. In 1988 the Seahawks traded him to the Indianapolis Colts for first-round draft picks in 1989 and 1990. He played three more seasons before a dislocated hip ended his career after the 1990 season.

In seven NFL seasons Young appeared in 101 regular-season games and started 79. He finished with 21 sacks and three interceptions. Team records credit him with 601 tackles.

At New Mexico State he was an All-American, a Hall of Famer and a member of the program’s Ring of Honor. He led the Aggies in tackles in 1982 and 1983 and still ranks among the school’s career leaders.

“His impact on Aggie Athletics, the game of football and the Las Cruces community will long be remembered,” NMSU Athletics said.

Young is survived by his wife and children.

For Seahawks fans who packed the Kingdome in the Knox years, he was the guy who arrived flying down the field on kickoffs and later filled the middle of the defense. Four seasons were enough to put him among the franchise’s all-time greats.