American Lion Attack Victim Identified as Katherine Chappell

— -- The American woman attacked and killed by a lion in a South African park has been identified by multiple sources as Katherine Chappell.

Chappell, whose identity was confirmed by her sister, was in her 20s, according to the sources.

The sister said the family is devastated, but declined further comment.

Chappell was attacked as she rode through the park Monday in a car driven by a tour operator, Scott Simpson, assistant manager at The Lion Park, told ABC News.

The tour operator driving the car was injured in the attack and remains hospitalized.

Witnesses quoted in South African media said the car's windows were open, contrary to park rules.

The Lion Park, near Johannesburg, South Africa, was "operating as usual" a day after the attack, Simpson said. However, the lioness was locked away in an enclosure and could be moved to a private location in the next day or two, Simpson added.

ABC News has learned the lioness had been mating and had cubs with her. That could help explain the attack.

The park is a popular tourist destination that allows visitors to drive in their own cars through large enclosures where lions roam freely.

ABC News' Sifiso Khanyile in South Africa, Hamish MacDonald, Liezl Thom and Jim Vojtech contributed to this report.