Former Hawaii star quarterback Colt Brennan died of a drug overdose, TMZ Sports reported.

The toxicology report showed that Brennan ingested fentanyl and other dangerous substances, which ultimately led to his death. Methamphetamine, amphetamine and ethanol were also found in his system.

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Health officials told TMZ Sports that Brennan’s death was accidental.

TMZ Sports also reported that it’s unclear if any of the drugs were prescribed to him by a doctor.

Brennan was a standout football player at Hawaii. In 2006, he completed 72.6% of his passes while throwing for 5,549 passing yards and 58 touchdowns. His passing yards total from that season is currently the seventh-most in FBS history, and his eye-popping touchdown total was a record until current Cincinnati Bengals quarterback Joe Burrow threw for 60 scores in 2019 for LSU.

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Instead of entering the NFL draft, Brennan decided to return to Hawaii for his senior season.

That year, Brennan led Hawaii to its first Western Athletic Conference title. He threw for 4,343 passing yards with 38 touchdowns and finished third in the Heisman Trophy voting. Brennan was the first player from Hawaii to finish as a Heisman finalist.

Brennan’s career at Hawaii was one of the best in college football history.

He finished with 14,193 passing yards and 131 touchdowns. Brennan is currently second in FBS history in passing yards per game, fifth in passing touchdowns, and eighth in passing yards.

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Brennan was a sixth-round draft pick by Washington in the 2008 NFL Draft. He played two seasons in Washington before joining the Oakland Raiders in 2010. Brennan also played in arena football, as well as the Canadian Football League.

When Brennan’s football career ended, he ran into trouble, including multiple arrests for drunken driving. In a 2010 car crash, Brennan suffered a traumatic brain injury.