ROUND LAKE, Ill. (CBS) — Six horses — including the grandson of legendary Triple Crown Winner Secretariat — were killed in a stable fire over the weekend in Round Lake.

As WBBM Newsradio’s Dave Marsett reports, the fire broke out on Saturday afternoon at the stable at at 24948 Nippersink Rd., according to Round Lake fire Capt. Bill Rohrs.

LISTEN: WBBM Newsradio’s Dave Marsett reports

He said someone was burning leaves nearby, and the flaming leaves in the windy conditions were to blame for a fire.

One firefighter sustained minor injuries and a civilian was treated at the scene, Rohrs said. The stable was completely destroyed.

Stable owner Urbano Hernandez breeds horses for racing and cutting. Cutting is an equestrian event where a horse and rider are judged on their ability to separate a single animal away from a cattle herd and keep it away for a short period of time.

“This is one of those unexpected things. I cannot even explain it myself — you never think something like this will happen to you,” Hernandez said.

Hernandez said the stable was home to some of the best bloodlines in racing. The six horses that perished included Secretariat’s grandson, Risky.

Secretariat sired 653 foals before dying in 1989.

“These horses were one of the best lines in the industry,” Hernandez said. “It’s a big loss (that) I’m not going to recoup.”

Also killed in the fire were the pregnant Chickes, Estrella, Princess, Paloma and AP Prince.

Hernandez said he was able to save three horses, and is planning to rebuild.

The Lake County News-Sun contributed to this report, via the Sun-Times Media Wire.