SAN DIEGO -- Don Coryell, the innovative coach whose Air Coryell offense produced some of the most dynamic passing attacks in NFL history, has died. He was 85.

The San Diego Chargers confirmed Coryell died Thursday at Sharp Grossmont Hospital in suburban La Mesa. The team did not release the cause of death, but Coryell had been in poor health for some time.

"We've lost a man who has contributed to the game of pro football in a very lasting way with his innovations and with his style," Pro Football Hall of Famer Dan Fouts, the quarterback who made Air Coryell fly, said from Oregon. "They say that imitation is the highest form of flattery -- look around, it's there."

The innovations of Don Coryell, left, gave birth to Air Coryell, the inspiration for the modern-day offenses that dominate the NFL. George Rose/Getty Images

Coryell was one of the founding fathers of the modern passing game. He coached at San Diego State from 1961 to 1972 and went 104-19-2. He left the Aztecs for the St. Louis Cardinals in 1973. With Jim Hart at quarterback, the Cardinals won division titles in 1974 and '75 behind Coryell.

Fouts said he became friends with Coryell after the two were finished with football.

"It's not just me," Fouts said. "All his players, Aztecs, Cardinals, Chargers, to a man, would tell you that he was their friend."

Coryell returned to San Diego when he was hired by the Chargers on Sept. 25, 1978, the same day a Pacific Southwest Airlines jet crashed into a North Park neighborhood after colliding with a small plane, killing all 137 people on the two planes and seven people on the ground.

"It's crazy that when you look back at the history of this city, he got hired on the same day as that PSA crash," said Hank Bauer, who was a running back and special teams star with the Chargers then. "That really was one of the darkest days in this city's history and it became one of the brightest days in the history of sports.

"He walked in and met our team for the time and he was just this little bundle of energy, flying around the meeting. He said, 'You know what? We're going to have fun, and we're going to cry and laugh and battle our [behinds] off, but we're going to have fun.' We had fun for a lot of years."

From 1978 to 1986, Air Coryell -- led by Fouts -- set records and led the NFL in passing almost every season. Coryell guided the Chargers to the AFC Championship Game after the 1980 and '81 seasons, but he never reached the Super Bowl.

The lack of a Super Bowl on his résumé may have hurt Coryell last winter in voting for the Pro Football Hall of Fame. He was a finalist for the first time, but was not selected for induction.

"He revolutionized the game of football, not only in San Diego, but throughout the entire NFL," Chargers president Dean Spanos said in a statement. "Don Coryell was a legend not only with the Chargers but throughout San Diego. Though unfortunately he did not live long enough to see it, hopefully one day his bust will find its proper place in Pro Football's Hall of Fame. He will be missed."