Former Hawaii quarterback Colt Brennan, 37, has died. His father, Terry Brennan, confirmed Colt's death to the Honolulu Star-Advertiser on Tuesday.

Terry Brennan told ESPN that his son attempted to check into a detox facility in California on Monday but was turned away because the facility had no beds available at the time. Colt was at a hotel on Monday where he ingested a substance laced with fentanyl, leading to the paramedics to be called. 

Colt Brennan, who battled personal demons throughout his life, died Tuesday morning at Hoag Hospital in Newport, California, after never regaining consciousness. 

"It caught up to him, you know?" former Hawaii coach June Jones told CBS Sports' Dennis Dodd. "So sad. He could have owned the whole world over here."

Brennan was the signal-caller of the high-flying Rainbow Warriors offense from 2005-07. He threw for 14,193 yards and 131 touchdowns in three seasons manning the Hawaii offense with his 58 touchdowns as a junior in 2006 breaking the single-season touchdown passing record previously held by Houston's David Klingler. Brennan's mark, which led him to a sixth-place finish in Heisman Trophy voting that season, was recently exceeded in 2019 by Joe Burrow, who finished with 60 touchdown passes for LSU.

Brennan followed that campaign with an incredible senior season in which he threw for 4,343 yards, 38 touchdowns and 17 interceptions. Hawaii finished 12-0 in the regular season and earned a berth in the Sugar Bowl against Georgia. Brennan was a finalist for the Heisman Trophy that year, finishing third in the voting behind Florida quarterback Tim Tebow and Arkansas running back Darren McFadden.

His career completion percentage of 70.4% is the best in FBS history. He also remains tied atop the FBS record books for most career passing games of 400+ yards (20) and most seasons of 4,000 or more passing yards (three). 

Brennan started his college career at Colorado in 2003 but was dismissed from the Buffaloes after the season following an arrest on burglary and trespassing charges. He transferred to Saddleback College in Mission Viejo, California, in 2004 before joining Hawaii and putting together his record-setting career.

"He was going to come out his junior year and elected to stay, which doesn't happen very often," Jones said. "Then he took us to that undefeated season, which doesn't happen very often." 

Brennan was selected in the sixth round of the 2008 NFL Draft by Washington. He spent two seasons with the team before being signed by the Oakland Raiders. He was cut by the Raiders prior to the start of the 2010 season. Brennan bounced around several leagues before giving up his football career in 2014.