HBO has debuted the first trailer for its upcoming two-part documentary, "Leaving Neverland," which features firsthand accounts from two men who allege that late pop superstar Michael Jackson sexually abused them when they were children.

"Leaving Neverland" chronicles the experiences of James Safechuck and Wade Robson, who claim that Jackson -- who passed away in 2009 at age 50 -- abused them for years, beginning when they were 10 and 7 years old, respectively. In the trailer, the men and their mothers discuss what it was like to visit Jackson at his idyllic Neverland Ranch, which Robson describes as "magical," and offered "anything you could ever want as a child."

"He just came across as a loving, caring, kind soul," Robson's mother says of Jackson. "It was easy to believe that he was just that."

But Neverland was also the place where Robson and Safechuck say that Jackson abused them, and coerced them into silence. Now, Robson says, "I want to be able to speak the truth as loud as I had to speak the lie for so long."

Jackson's family has publicly condemned "Leaving Neverland," as have his fans, some of whom staged a small protest when the film debuted at the Sundance Film Festival earlier this year. Sundance attendees reportedly found the documentary so disturbing that several had to leave the screening midway through. Counselors were standing by in the lobby to speak with those upset by the events on screen.

"Leaving Neverland," directed by Dan Reed, will air in two parts, on March 3 and March 4, on HBO.