On May 25, 1979, 6-year-old Etan Patz disappeared while walking to the bus stop near his home in New York City. The frantic search for the boy drew national attention and raised awareness of child abductions, and Etan became the first child to appear on the side of a milk carton. But despite the efforts of the police, Etan was never found, and no criminal charges were ever brought against any suspect. Now, 33 years later, investigators are revisiting a basement in Etan's neighborhood that might solve the mystery of his heartbreaking disappearance. Here, a guide to the case:

What do we know about Etan's disappearance?
The bus stop was a block from Etan's apartment in the Manhattan neighborhood of SoHo, which in 1979 was much grittier than the chic shopping area it's become today. It was the first time Etan had walked to the bus stop by himself, and he had previously "pleaded with his parents that he was old enough to make the trip alone," say James Barron and William K. Rashbaum at The New York Times. The last time anyone saw him, he was wearing a pilot's hat, a blue corduroy jacket, and a cloth bag imprinted with elephants.

When did his parents realize he was missing?
His mother, Julie Platz, got worried when Etan failed to return home from school. She then found out that he had not been in class at all that day, and by evening "more than 100 police officers and searchers had gathered with bloodhounds" to hunt for the boy, say Susan Candiotti and Adam Reiss at CNN. The police conducted a "floor-by-floor, wall-by-wall, rooftop-by-rooftop, backyard-by-backyard search," say Barron and Rashbaum, but Etan was nowhere to be found. 

Were there any suspects at the time?
The prime suspect has long been Jose Antonio Ramos, who "dated a woman who walked Etan to school," says Jen Chung at Gothamist. Ramos is currently in prison for sexually abusing a child, but he has proclaimed his innocence in the case of Etan, and there has never been enough evidence to bring criminal charges against him.

What has happened since 1979?
In 1983, President Reagan named May 25 National Missing Children's Day after Etan. In 2001, Etan was declared officially dead. In 2004, a civil court ruled that Ramos was responsible for Etan's death, and ordered Ramos to pay Etan's family $2 million. "He never paid the money," say Candiotti and Reiss.

Why are authorities reopening the case now?
Etan's father, Stanley Patz, pressed former New York District Attorney Robert Morgenthau to reopen the case, but to no avail. "I realize this is not like CSI," he once said. "But there is enough evidence that a competent attorney can use to prosecute." Morgenthau's successor, Cy Vance Jr., decided to resurrect the case in 2010, though he "declined to give a reason," says Amberdoty at Babble, "stating only that he would like to take a fresh look at the evidence."

What new evidence has emerged?
Authorities were jolted into action this week after an interview with Othniel Miller, a handyman who used to work in Etan's building. Miller gave Etan a dollar for doing chores the day before he disappeared. When asked about the possibility that Etan was buried in a basement in Ramos' building, where Miller had a workshop, Miller, now 75, reportedly blurted out, "What if the body was moved?" Shortly afterward, a cadaver-sniffing dog "picked up a human scent in the basement," say Candiotti and Reiss. Authorities are now "working on the theory" that Miller "killed the boy and buried him there," say Barron and Rashbaum

What are investigators doing in the basement?
They are planning to spend as many as five days ripping up the floor and searching for the boy's clothing, human remains, or personal belongings. They are also looking for blood traces and other forensic evidence. Officials are reportedly "cautiously optimistic" that they will find something. Miller is currently not accused of any crime, nor is he in custody.

Sources: Babble, CNN, GothamistThe New York Times