CREVE COEUR — A single mother of three who owned a specialized exercise studio was killed when she walked in on an apparent burglary, her family said Wednesday.

Investigators are looking for two men in connection with the killing of Susan Schaffer, 48, who was shot to death between 4 and 4:30 p.m. Tuesday at her home in the 12900 block of Nimes Drive, police said.

Her family said investigators with the Major Case Squad of Greater St. Louis told them it does not appear Schaffer knew the killer.

Schaffer was the owner of Spiral Power, a studio in an office building at 7700 Clayton Road in Richmond Heights that focuses on a form of movement and exercise similar to pilates.

Schaffer raised three children by herself after her divorce 14 years ago, said her brother, Eric Schaffer. Her three children have the last name of their father, Wenig.

Rachel Wenig, 23, is a paralegal in New York City. Daniel Wenig, 18, and Sarah Wenig, 16, are students at Parkway North High School.

"She was one of the most beautiful people in the world," Eric Schaffer said. "She was caring and loving, a selfless person, a wonderful mother, the best daughter, a great sister and a great aunt. It's a tragedy we have lost such a beautiful person in such a random way."

Schaffer was a lifelong fitness buff, her family said. She started her career as a dancer before becoming an aerobics and pilates instructor, which she has done for more than 25 years. She grew up in Great Neck, N.Y., and graduated from Skidmore College in upstate New York.

She opened her own studio a little more than a year ago.

When Schaffer was not spending time as a mother or business owner, she also loved to cook.

For the family's Thanksgiving dinner, she rushed out before the meal to buy an array of vegetables so she could add a few additional dishes to the feast, said her father, David Schaffer.

Schaffer's parents and brother arrived in St. Louis from the East Coast on Wednesday and are caring for her children.

"We're coping by just trying to be together and be there for everyone," David Schaffer said. "It's not easy, but we're doing the best we can and we will eventually get through this together."

Schaffer lived on a quiet, tree-lined street in a subdivision south of Olive Boulevard's intersection with Fee Fee Road. One of her neighbors, Bryson Hartranft, said the only crime in the area had been the occasional car break-in.

"It's shocking," Hartranft said. "Unbelievable. As the father of two children, quite frankly it's the most troubling thing you can think of."

Schaffer's family said she appears to have been in the wrong place at the wrong time.

"I have to believe this is a random, unexplainable event in this crazy world of ours that defies every logic whatsoever," Eric Schaffer said.

Funeral services are scheduled for Sunday in Great Neck, N.Y. A St. Louis-area memorial service will be held later.

poconnell@post-dispatch.com | 314-863-2821