Aubrey McClendon, a billionaire entrepreneur who founded a natural gas business that twice made the Inc. 5000 list of the country's fastest-growing companies, has died.

McClendon, 56, who founded Chesapeake Energy Corp. in 1989 and served as its chief executive, is credited with leading the domestic energy boom. His company is known for spearheading the rise of hydraulic fracturing, or fracking, the controversial process where natural gas is removed from deep within underground shale deposits by injecting water and chemicals at high pressure.

On Tuesday, McClendon had been indicted on federal charges of bid-rigging and conspiring to suppress prices on oil and natural gas leases between 2007 and 2012, The New York Times reported. The following day, he died after his car reportedly hit a bridge outside of Oklahoma City at high speed. An investigation into the causes of the crash is ongoing.

McClendon had a reputation for extreme risk taking in his business, and was named America's "Most Reckless Billionaire" in a 2011 Forbes cover story, for his willingness to grow rapidly through leverage. In addition to an oil enterprise that rivaled ExxonMobil for natural gas extraction, McClendon owned a winery in France, and was part owner of the NBA's Oklahoma City Thunder.

"He was charismatic and a true American entrepreneur," T. Boone Pickens, a corporate raider and also an oil prospector, told news sources on Wednesday. "No individual is without flaws, but his impact on American energy will be long-lasting."

In 1989, McClendon also founded the subsidiary Chesapeake Oilfield Services, of Oklahoma City, Oklahoma. The company appeared on the Inc. 5000 in 1997 at No. 268,  and again in 2012 at No. 2,442. The company provides infrastructure services including well rigging and drilling equipment and trucking services.

Chesapeake Oilfield filed papers to go public in 2012, but withdrew its offering in 2014 for unspecified reasons. McClendon was ousted from the parent company in 2013, for reportedly taking out more than $1 billion in loans against his ownership stake in the company to finance more drilling operations. The same year, he founded competing natural gas company American Energy Partners.