The car, which was locked, held no signs of foul play or clues as to where Zizzamia might have gone or why. Investigators were unable to determine where the phone call had originated.
In the 35 years since, no sightings have been reported, no body has been recovered, and no evidence has emerged that Zizzamia's Social Security number, driver's license, or Amoco gasoline credit card was used again.
"It's like he fell off the face of the earth," says Cherry Hill Police Detective Paul Hafner, who reviews the case annually. "It's baffling."
Zizzamia may have wanted it that way.
"Nick once told me he'd found a way to kill himself that would be painless, and no one would ever find him," says Peter Stratis-Quarelli, 59, who describes himself as Zizzamia's best friend at Bishop Eustace Preparatory School.
A photograph in the Eustace yearbook shows them smiling and smoking together. It appears to be Zizzamia's only appearance in the 1974 Crusader, other than his official class photo.
"Nick was a nice, nice person," Stratis-Quarelli says. "I don't know any other way to say it."
I reach Stratis-Quarelli through Richard W. Bannar, director of alumni relations at Eustace, who tells me Zizzamia seems to have "flown under the radar" at the Pennsauken school.
A veteran faculty member "has no memory at all" of Zizzamia, says Bannar, who asked longtime staffers about the missing graduate at my request.
A classmate who was in the same homeroom barely knew Zizzamia, either.
"He was a quiet, easygoing guy who sat a few seats behind me in homeroom from 1970 to 1974," says Tom Wilk, 58, a freelance writer in Pitman.
But Stratis-Quarelli says Zizzamia confided in him one spring day during senior year.
"He told me, 'I'm just going to vanish.' I said: 'Come on, man. What are you going to do? Maybe I might want to join you,' " Stratis-Quarelli says from his home in Margate. "But Nick wouldn't talk about it."
Much went unsaid between the two friends, according to Stratis-Quarelli, who grew up in Merchantville and often went to Zizzamia's house to study. He says his friend was "one of the smartest people I ever knew" but nevertheless was haunted by feelings of failure.
Zizzamia also was "very sensitive" about his weight, which the missing-persons website of the New Jersey State Police lists as 290 pounds.
"Nick was very sensitive about life in general," Stratis-Quarelli says. "He had some gay tendencies. We didn't discuss it in depth, but we both knew it was there. He kind of danced around the subject."
After hanging out at the Shore together in the summer of 1974, hitting Bayshores and other clubs, they fell out of touch. Some time later, after Stratis-Quarelli opened Pistol Pete's, a pizzeria in Haddon Heights, Zizzamia's mother, Marie, came through the door.
"She said: 'Can you talk to Nick? He's very depressed. He's not doing well in school, he's not studying,' " says Stratis-Quarelli, adding that he was unable to reach his friend.
"I knew Nick didn't want to go into his father's business, and he didn't want to go to Villanova," he adds. "I think he failed on purpose."
Villanova records indicate that Zizzamia attended the university from September 1974 until May 1979 but did not graduate. University officials said Friday that they could not immediately determine whether Zizzamia would have graduated had he not gone missing.
"Common sense tells you that either this was something that was planned, or an event occurred that prevented him from coming home," Hafner says. "But you just don't know."
Sometime after their only child disappeared, Zizzamia's parents divorced. His mother died in 2003, and his father, Nicholas, a U.S. Marine awarded a Purple Heart after being wounded in action at Iwo Jima in 1945, died in 2012. An online obituary makes no mention of the son he had lost.
"I've always wondered, What did Nick do? Where did he go?" says Stratis-Quarelli, who spoke to investigators in 1979 and, last week, to Hafner as well. "I've never forgotten him. I've prayed for him."
And when my e-mail about Zizzamia arrived, "I got excited," Stratis-Quarelli says. "I thought, Maybe somebody found him."
Anyone with information about the disappearance of Nicholas Peter Zizzamia can contact Cherry Hill Police Detective Paul Hafner at 856-432-8824 or firstname.lastname@example.org.