They left for a concert.
They never came home.

Two Brooklyn kids, one summer weekend

In the summer of 1973, the biggest event in rock and roll was Summer Jam at the Watkins Glen Grand Prix Raceway — a single-day festival headlined by the Grateful Dead, the Allman Brothers Band, and The Band. Roughly 600,000 people made the pilgrimage to upstate New York, making it one of the largest concert gatherings in American history.

Among those determined to be there were two teenagers from Brooklyn: Mitchel Weiser and Bonnie Bickwit. They had been dating for over a year, both students at John Dewey High School — an alternative Brooklyn school for gifted, high-achieving students. Both came from stable, middle-class Jewish families. Neither had any history of running away.

On July 26, Mitchel took a bus from Manhattan's Port Authority to Narrowsburg in Sullivan County, where Bonnie was working a summer job as a mother's helper at Camp Wel-Met. Bonnie quit her job to make the trip — telling her employer she'd be back afterward to collect her paycheck.

The next morning, July 27, the couple set out to hitchhike roughly 150 miles northwest to Watkins Glen. They carried backpacks, sleeping bags, about $25, and a cardboard sign that read simply: "Watkins Glen." Mitchel, a photographer's assistant, brought his camera. They were last seen hitchhiking along State Route 97.

They were never seen again. Out of some 600,000 people who went to Summer Jam, Mitchel and Bonnie are the only two known attendees who vanished.

"Hippie runaways": how the system lost them twice

When Mitchel failed to return home that Sunday, his mother, Shirley, contacted the authorities. What followed was one of the most thoroughly documented investigative failures in New York missing-persons history.

Police in Sullivan County, Schuyler County, and New York City dismissed the pair as "hippie runaways" who would turn up on their own. The NYPD assured Mitchel's father that state agencies would be alerted — they never were. A September 1973 letter from Wall Street Journal editor Martin Hollander to NYPD Commissioner Donald Cawley documented the neglect, noting that valuable time was lost and that Mr. Weiser had been treated abusively by officers.

Sullivan County became the lead agency but did minimal work. Over the years, the original case files, witness lists, and investigators' notes were lost — along with the teens' dental records, which could have identified remains. A 1998 newspaper investigation by Eric J. Greenberg laid out the incompetence in detail; a former NYPD Missing Persons Squad commander admitted the files had been lost "early on."

So the families did the police's job themselves. They papered Sullivan and Schuyler counties with thousands of fliers, placed ads in underground newspapers nationwide, hired private detectives, and visited communes, reservations, and religious movements from the Hare Krishnas to the Unification Church. Mitchel's sister, Susan Weiser Liebegott, went undercover inside the Children of God cult searching for her brother.

Fifty-three years of searching

Someone still remembers something

Investigators believe the answer likely lies with an ordinary person: someone who was on Route 97 or at the festival that weekend, someone who saw two teens at a river along the Susquehanna, someone who inherited an old Japanese camera — or someone whose relative said something, once, that never sat right.