A Mandeville teenager on her way to a horse show in Mississippi was killed in a three-vehicle wreck Thursday evening on Miss. 53, north of Gulfport.

Brooke Posey, 17, died when her southbound 2005 Honda Civic ran into the rear of a 1999 Chevrolet Silverado pickup that was stopped to make a left turn onto Carlton Cuevas Road about 5:45 p.m.

According to Harrison County Sheriff Troy Peterson, a 14-year-old male passenger in Posey's vehicle was taken to Gulfport Memorial Hospital.

Mississippi Highway Patrol spokesman Chase Elkins said that after Posey’s vehicle crashed into the 1999 Silverado, it collided head-on with a 2014 Silverado pickup headed northbound on the highway. The 2014 Silverado then hit a boat being towed by a 2007 Toyota Tundra pickup.

Elkins said the 2014 Silverado rolled over several times, ejecting the driver. He suffered severe injuries and was flown to a hospital in Mobile, Alabama.

According to an article published online in The Chronicle of Horse magazine, Posey and Grayson Bell, her barn mate, were on their way to the Harrison County Fairgrounds & Equestrian Center in Gulfport for the final weekend of the Gulf Coast Winter Series.

Posey had been competing in the six-week-long series in the children’s/adult jumper division, receiving the reserve champion tricolor during the first weekend.

Posey had trained for two years under the watchful eyes of T.J. LeBlanc and his daughter, Katherine, of Fox Ridge Farm in Folsom.

"It was refreshing to have her around," Katherine LeBlanc said. "The care and love she showed the horses showed just how special she was."

Posey was an extremely hard worker, LeBlanc said. "She would set a goal, and no matter how many times she had to do something, she never became discouraged, and she stayed after it until she met that goal."

LeBlanc described Posey as "being like my little sister. She went on vacations with us, and she became like she was part of our family."

Posey had planned to attend LSU in the fall.

Her funeral will be at 2 p.m. Wednesday at Hosanna Lutheran Church, 2480 U.S. 190, Mandeville.