Norman, Okla. ? Police were investigating whether drugs had a role in the death Thursday of Oklahoma senior linebacker Austin Box, and a witness told authorities he believed his friend had overdosed.

Authorities didn’t immediately release an official cause of death, and Box’s body was sent to the state Medical Examiner’s office. Box was 22.

“We’re all shocked and heartbroken,” Oklahoma football coach Bob Stoops said in a statement. “Austin was a great young man, a great young man to coach, and a great teammate.”

Stoops’ defensive coordinator, Brent Venables, fought back tears and said he was “numb” while talking about Box during an evening news conference at the Switzer Center, adjacent to the Gaylord Family-Oklahoma Memorial Stadium.

“You can’t plan for this,” Venables said. “There’s no blueprint for it. I just know that a young man was tragically taken from us today.”

El Reno Police Chief Ken Brown said officers and medics responded to a call at a house in the town about 30 miles west of Oklahoma City about 9:25 a.m. concerning an unresponsive male “with unknown medical issues.” Brown identified the man as Box and said he first was taken to an El Reno hospital, then transferred by air ambulance to Mercy Hospital in Oklahoma City.

Cycling

Hamilton: Armstrong doped

New York — Tyler Hamilton, a former teammate of Lance Armstrong, told “60 Minutes” that he used performance-enhancing drugs with the seven-time Tour de France winner to cheat in cycling races, including the tour.

Hamilton said Armstrong took a blood-booster called EPO in the 1999 Tour and before the race in 2000 and 2001. Armstrong won the race every year from 1999-2005.

The interview with Hamilton was broadcast on the “CBS Evening News” on Thursday.

“I saw (EPO) in his refrigerator. … I saw him inject it more than one time,” Hamilton said, “like we all did. Like I did, many, many times.”

Hamilton told “60 Minutes” reporter Scott Pelley: “(Armstrong) took what we all took … the majority of the peloton,” referring to riders in the race. “There was EPO … testosterone … a blood transfusion.”

EPO is a drug that boosts endurance by increasing the number of red blood cells in the body.

Armstrong has steadfastly denied doping and has never failed a drug test. However, federal authorities are investigating whether Armstrong and his former U.S. Postal team did participate in a systematic doping program.

Hamilton’s accusations come a year after Floyd Landis, another former Armstrong teammate, made similar allegations of drug use by Armstrong and the team. And like Landis, Hamilton said Armstrong failed a drug test at the 2001 Tour de Suisse.

Armstrong’s attorney Mark Fabiani dismissed the “60 Minutes” report.

Shortly after Hamilton’s comments aired, Armstrong launched a website that refuted the claims and tweeted: “20+ year career. 500 drug controls worldwide, in and out of competition. Never a failed test. I rest my case.”

Hamilton won a cycling gold medal at the 2004 Athens Games but failed a drug test later. He was allowed to keep his medal, however, because problems at a laboratory meant his backup ‘B’ sample could not be tested.

Months later, he was caught blood doping and served a two-year ban which ended in 2007.

Sagan wins fifth stage

Paso Robles, Calif. — Slovakian Peter Sagan swung wide right in the final 100 yards and sped from fifth place to win the fifth stage of the Tour of California.

Chris Horner remained the overall race leader Thursday.

TV

Ebersol resigns from NBC

New York — Dick Ebersol, who made NBC the TV home of the Olympics for more than two decades, will watch someone else run the network’s coverage of next year’s Summer Games.

The powerful TV executive behind shows from “Saturday Night Live” to “Sunday Night Football” resigned Thursday as head of NBC Sports in a contract dispute with his new bosses at Comcast.

The break was sudden and unexpected: Ebersol had been given a promotion when Comcast took over NBCUniversal earlier this year and appeared Monday at a presentation NBC gave to advertisers in New York, tossing footballs from the stage and talking about coverage of the 2012 London Olympics.

Now, he said he’ll be an uninvolved spectator.

“I think it’ll be fun once I get past thinking, ‘I would’ve done that differently,”‘ he said Thursday.

Ebersol, who is married to actress Susan Saint James, survived a plane crash that killed their teenage son in 2004.

He has had a profound effect on what the nation has watched on television since the 1970s — and his exit could portend big changes in the TV landscape in the next decade.

Ebersol said he wanted “to make a really cool deal” with Comcast executives. “We just couldn’t get to the same place.” His nine-year contract with NBC was due to expire at the end of next year.

“I had a long run and loved every bit of it,” Ebersol said in a phone interview with the Associated Press on Thursday.

Baseball

Royals demote Dyson

Kansas City, Mo. — The Kansas City Royals made four roster moves on Thursday, including activating right-hander Robinson Tejeda from the disabled list.

In addition, the Royals brought up right-hander reliever Greg Holland from Triple-A Omaha and sent outfielder Jarrod Dyson and right-hander Jeremy Jeffress to Omaha.

Golf

Toms, Reavie share lead

Fort Worth, Texas — David Toms quickly rebounded from the disappointment of his near-miss.

Four days after losing in a playoff at The Players Championship. Toms shot a bogey-free 8-under 62 on Thursday to share the first-round lead at Colonial with Chez Reavie.

After forcing a playoff with K.J. Choi at TPC Sawgrass with a rare birdie at the 18th hole, Toms missed a short par putt at the famed No. 17 island hole in the playoff that would have extended play.

Westwood routs Hansen

Casares, Spain — Top-ranked Lee Westwood routed Anders Hansen, 6 and 5, on the opening day of the Volvo World Match Play Championship, sending a message to two players trying to take the top spot.

Luke Donald and Martin Kaymer, who could move to the top of the rankings by winning the tournament, also eased to victories in the opening round-robin matches at Finca Cortesin.

Webb upends Kemp

Gladstone, N.J. — Hall of Famer Karrie Webb beat fellow Australian Sarah Kemp, 3 and 2, to set up a second-round match match with Paula Creamer in the Sybase Match Play Championship.

Creamer, the U.S. Women’s Open champion, topped Aree Song, 5 and 4, at Hamilton Farm Golf Club.

Auto racing

De Silvestro hurt in crash

Indianapolis — Swiss driver Simona De Silvestro burned both hands in a crash during Indy 500 practice Thursday, threatening her participation in qualifying Saturday and Sunday.

HVM Racing owner Keith Wiggins said there’s an outside chance the team would bring in another driver to get De Silvestro’s backup car qualified, then bring her back to start the May 29 race at the back of the field.

The 22-year-old De Silvestro has second-degree burns on her right hand and superficial burns on her left, track officials said. She was able to walk to a vehicle that took her to the track’s medical center, then was transported to a hospital. De Silvestro later tweeted a photo of her bandaged hands from outside the hospital.

Hamlin’s crew wins title

Charlotte, N.C. — Denny Hamlin and his crew finished 39 points shy of ending Jimmie Johnson’s dominance last year in NASCAR’s Sprint Cup title chase.

Hamlin’s team exacted a little revenge Thursday night — without Hamlin behind the wheel.

“We know where the weakest link is, obviously,” Hamlin said, smiling.

Hamlin’s No. 11 team successfully defended its title in NASCAR’s Pit Crew Challenge by edging Johnson’s No. 48 crew in the final round, producing smiles, champagne soaked firesuits and confidence of a potential repeat win come November that would end Johnson’s five-year dominance as Cup champion.