Aubrey McClendon, a founder and former chief executive of Chesapeake Energy, died in a fiery single-car crash Wednesday, a day after he was charged with conspiring to rig bids for oil and natural gas leases. McClendon, 56, crashed into an embankment while traveling at a "high rate of speed" in Oklahoma City just after 9 a.m. local time, said Capt. Paco Balderrama of the Oklahoma City Police Department. Flames engulfed McClendon's vehicle "immediately," Balderrama said. He added that police determined McClendon was not wearing a seatbelt after earlier being unable to tell. "He pretty much drove straight into the wall," Balderrama said. He said police still needed to determine an exact cause of the crash, but a medical event was "possible." McClendon was expected to turn himself in at 11 a.m., Balderrama added.

The car crash site of Aubrey McClendon, former CEO of Chesapeake Energy, in Oklahoma City on March 2, 2016. Source: KFOR | NBC

McClendon — a key player in the U.S. shale boom — co-founded Chesapeake in 1989 and stepped down from the company in 2013. Chesapeake is the second-largest natural gas producer in the United States. He also founded American Energy Partners, where he had been chief executive. McClendon, a Duke University graduate, was a part owner of the National Basketball Association's Oklahoma City Thunder. The team plays its home games at Chesapeake Energy Arena.

"Aubrey's tremendous leadership, vision and passion for the energy industry had an impact on the community, the country and the world. We are tremendously proud of his legacy and will continue to work hard to live up to the unmatched standards he set for excellence and integrity," American Energy Partners said in a statement.

Chesapeake said in a statement that it is "deeply saddened by the news" and its "thoughts and prayers are with the McClendon family during this difficult time." McClendon had denied the antitrust charges against him. The alleged conspiracy took place between December 2007 and March 2012, Tuesday's federal indictment said. The companies are accused of deciding who would win certain oil and natural gas bids, then giving an interest in the leases to the other company. The Justice Department did not say which other company it believes was involved in the alleged scheme.

"Anyone who knows me, my business record and the industry in which I have worked for 35 years, knows that I could not be guilty of violating any antitrust laws," McClendon said in a statement Tuesday.