Kaley Cuoco, a 17-year-old Thousand Oaks resident and Camarillo native, has starred with Ritter in "8 Simple Rules," playing Bridget, the older daughter of Ritter's character, Paul Hennessy.
Gary Cuoco, Kaley's father, said Friday that she was too upset to take any calls about Ritter.
"He was a very close friend. He cared very much about her, and the feeling was mutual. He was almost like a second father," Gary Cuoco said.
In an interview in May, Kaley Cuoco said everything about the TV show, including her friendship with Ritter, exceeded her expectations.
She said Ritter acted like a father to her even when the cameras weren't rolling.
Just like her real-life parents, Ritter would express concern about her clothes, telling her to wear a jacket if he didn't think her clothes were enough to cover her up.