"Well, they ignored me. They said I was hysterical," she says. "And I said, 'Well, when was I hysterical?' I never screamed or hollered or cried or did any of that. I mean, [I] was just concerned. Where is my son? He isn't home. What are you gonna do about it?"
Police didn't do much.
"They said, 'Well, you know, he's 18. You just sorta have to wait and he'll come up. He'll show up,'" Flossie Klee tells 48 Hours Mystery correspondent Erin Moriarty.
Even if police had begun a serious search, it wasn't so easy to track down a missing teen in the late 1970s. There weren't surveillance cameras everywhere or ATM's on every corner, as there are today; there were no cell phones, electronic tolls or other vast computer networks.
In the 1970s, drinking laws were more lax, too. It was perfectly legal in Florida for 18-year-olds to drink at bars. Nickel beer night at the Crown Lounge was a big hit with Jeff Klee and his friends.
Alan Carpenter was one of those close friends. "Jeff was - he was a lot of fun. He was a party maker," he says. "[Jeff] just enjoyed having a good time."
Ginny Healy was Jeff's girlfriend. "He was strong and I thought he was handsome. Like a man's man. Even at 18, it's like he knew he was." When asked if she loved Jeff, Healy says, "absolutely."
As the oldest of four children, Jeff was also close to his mother and three younger sisters; DeeDee was 11 when her brother disappeared.
"I remember sitting in the front yard for hours, 'cause I was waiting for him to come home," she recalls. "And [Mom's] like, 'OK. You know, it's time to come in, Dee Dee.' I'm like, 'But he's not home yet.'"
Cyndy, now a Coral Springs cop, was 15.
"He'd give you the shirt off his back -- to anybody, even his sisters, believe it or not," she says.
Laurel, who was only a year younger than Jeff, was closest to him. She hung out with her brother and his friends - especially his best friend, David Cusanelli.
"They did everything together," Laurel says, "and he was like a big brother to me."
Flossie says David and Jeff "were almost inseparable."
David Cusanelli and Alan Carpenter worked for Jeff's dad, Bucky, who ran a landscaping business. Bucky had a commanding presence and expected his son to someday run the company. Jeff was given half of the business and he had a brand-new van.
Ginny Healy says that while Jeff liked working in his father's business, "I also think that he'd get a little resentful only because he worked so much."
Jeff's disappearance was tough for Bucky.
"This is his boy. It left a big void with him in his life, I think," says Flossie, who vividly recalls the last time she saw her son. "It was in my family room. And he was going out. I can see him. And we were all laughing in the family room doin' somethin'. And I remember him sayin' to me, 'Mom, I love you.' And that was the last time I remember that."
"Jeff, from what I understand, left the Crown Lounge. He went to take David Cusinelli home and never returned home himself," says Laurel.
"What I recall is Cusinelli telling me that Jeff had disappeared. That his mother was looking for him. And, 'Have you seen him?' And I said, 'No, and I haven't heard from him,'" Healy recalls. "He always mentioned when he'd go off daydreamin' that he would move to California. And I thought he went."
Carpenter says he and others also thought Jeff went off on his own. "Find a place down in the Keys. He had a scuba license. He loved the water."
As time wore on, there was still no sign of Jeff. As part of procedure, police took a closer look at his family and learned that Bucky Klee was a gambler.
"My husband knew a lot of people and not all of 'em were wonderful people. Bucky did like to gamble. He knew bookies," says Flossie, who believes there's no connection between her husband's gambling and their son's disappearance.
The police also learned that the Klees had taken out a $100,000 life insurance policy on Jeff.
"Wasn't that a pretty large insurance policy on an 18-year-old?" asks Moriarty.
"Well, probably," Flossie admits. "My girls also had large policies on them too. This was just something we did."
Cyndy says her mother refused to believe that Jeff was dead, even buying him Christmas gifts the first year he was missing, so he'd "have something to open up when he comes in, you know, through the front door."
Jeff's sisters began to wonder if the friend who last saw their brother might be hiding something. David had stopped working for their father right after Jeff disappeared.
Laurel says she saw David from time to time and even asked him what happened to her brother. "I really thought that he knew something, but I didn't know what," she says. "And I asked him and he just said, 'He didn't know.'"
In 1981, four years after Jeff disappeared, suddenly there was news: Someone Jeff knew says he is alive.