WAPATO, Wash. -- For most of her life, Trudi Lee Clark wondered what happened to her sister, Janice Marie Hannigan.

Hannigan was 16 and a sophomore at White Swan High School when she was hospitalized on Dec. 21, 1971, for treatment of bruises on her chest and head. She was discharged on Christmas Eve in satisfactory condition, according to a doctor’s summary.

“But where did she go after this?” her sister asked in an October interview.

Lee Clark, whose search for her missing sister intensified after her parents passed away without answers, died early Dec. 23.

Dressing services will be held at the Toppenish Creek Longhouse at 2 p.m. Thursday with overnight services to follow. Funeral services will be at sunrise Friday at the Toppenish Creek Cemetery. Heggie’s Colonial Funeral Home is in charge of arrangements.

Born on Aug. 6, 1963, in Toppenish, Lee Clark was the daughter of Sally George Hannigan and Martin J. Hannigan. She was the second youngest of their seven children and a strong advocate for murdered and missing women, her obituary notes.

Her sister, born on March 22, 1955, was their parents’ oldest child. Lee Clark was 8 when Janice went missing. At the time their parents were separated and Janice lived with her father in Harrah while the six younger children were with their mother in Buena, Lee Clark said.

Their mother asked many people over the years about what might have happened. Like others with missing relatives or friends, the family had to navigate all kinds of rumors about where she might be.

“She didn’t know what happened, where she was, who she was last with,” Lee Clark said of their mother. “She interrogated a couple of her boyfriends she had; they would just tell her they didn’t know where she was.”

The passage of time didn’t diminish their mother’s loss, Lee Clark said. A soft-spoken woman who became emotional when talking about her sister, Lee Clark felt the same way.

“If anyone knows anything about where my sister is or where she was last seen, please, please come forward. Both my mom and dad never got closure before passing on,” she said in October.

Martin Hannigan died in 1989; their mother in 2001.

“People tell me to just let her rest in peace. I’m like, rest in peace where? I don’t know if she’s alive or dead. If she’s dead, bring her home to our cemetery,” she said.

A missing person report on Janice Marie Hannigan appears on The Charley Project, a website that profiles profiles approximately 10,000 “cold case” missing people, most from the United States. See it here.