Investigators have not ruled out the possibility of arson in a Labor Day fire that killed 29 thoroughbreds and destroyed three barns behind the Charles Town Racetrack in West Virginia.

A 911 call was made at 4:41 a.m. Monday, though witnesses reported seeing smoke and flames at 4:20 a.m.

Patrick Barker, assistant state fire marshal, said authorities are investigating whether the fire was intentionally set.

“There has been some evidence taken from the scene that might show indications of a criminal act,” Barker said. “We’re not labeling it as that until we can confirm a few things.”

Charles Town, which opened in 1933, runs year-round racing. The barns, located across from the ­racetrack’s parking garage, were old, wooden buildings that were not policed by overnight security — unlike the on-track stabling. Firefighters and rescuers were able to remove 26 horses from the barns safely.

“It was feeding time, and a lot of people saw the fire going, but it all happened very quickly,” said Ken Lowe, president of the Charles Town Horsemen’s Benevolent & Protective Association.

Two people, an employee of the track-affiliated casino and a firefighter, suffered minor injuries in the fire.

Breeders’ Cup Sales Nearly Double

Ticket sales for the Nov. 5-6 Breeders’ Cup at Churchill Downs are nearly double the 2009 number through the same time period.

Breeders’ Cup officials report ticket sales for the two-day event totaling $7.2 million (through Labor Day), compared with $3.7 million last year. The rise in interest could be attributed to a potential showdown between the two super mares, undefeated Zenyatta and 2009 Horse of the Year Rachel Alexandra, in the $6 million Breeders’ Cup Classic — won last year by Zenyatta.

However, Rachel Alexandra’s owner, Jess Jackson, has yet to commit the 4-year-old filly to any of the Breeders’ Cup races. In her most recent start, the Aug. 29 Personal Ensign Stakes at Saratoga Race Course, Rachel Alexandra surrendered the lead to a 21-1 longshot in the homestretch for her third loss in five races this year.

Zenyatta, whose record stands at a perfect 18-for-18, will prep for a defense of her Classic title in the Oct. 2 Lady’s Secret at Hollywood Park.

American Eventing Championships on Tap

This weekend’s American Eventing Championships is also serving as the final selection trials for U.S. riders hoping to compete in the Alltech FEI World Equestrian Games at the Kentucky Horse Park in Lexington next month.

Will Faudree, of Hoffman, and Holly Hudspeth, formerly of Southern Pines, now based in Rougemont, are short-listed for the U.S. team.

O’Neill Cited Again

For the second time this year, leading trainer Doug O’Neill has been cited for having a horse test for an excessive amount of total carbon dioxide (TCO2), according to the California Horse Racing Board.

The process, known as milkshaking, involves administering a baking soda mixture to a horse immediately before a race. The “milkshake” neutralizes lactic acid buildup and delays muscle fatigue. The process is banned in all racing jurisdictions.

O’Neill, who wrapped up his fourth Del Mar training title last week, recently came under fire for his ­handling of the mare Burna Dette, who broke down in the $2,000 claiming race at Los Alamitos and had to be ­euthanized. His horse Argenta, an eighth-place finisher in the sixth race at Del Mar on Aug. 25, is the subject of the CHRB’s complaint.

Dr. Rick Arthur, the racing board’s equine medical director, said O’Neill could receive a minimum 30-day suspension based on Argenta’s TCO2 levels

In April, the O’Neill-trained Stephen Got Hope tested for an excess of TCO2 at the Illinois Derby. O’Neill served a 15-day suspension for that infraction. This would be O’Neill’s fourth milkshake violation (he had one in 2007 and another in 2008). O’Neill has won 24 training titles at California tracks since 2002.