GROWING UP AS THE "WORLD'S STRONGEST BOY" -- 12-YEAR-OLD RICHARD SANDRAK TALKS ABOUT HIS RISE AND FALL AS A BODYBUILDER TO BILL RITTER ON "20/20," FRIDAY, MARCH 11 ON ABC

Also: Brian Ross' Exclusive Report on the Circumstances Behind the Deaths of Four American Civilians Ambushed and Hung from a Bridge in Fallujah, Iraq Last Year; And John Stossel's Give Me a Break: What is Art?

Richard Sandrak began lifting barbells at the age of three, had a six-pack by five and was a weightlifting sensation by six. Experts have said that at one point, this "little Hercules" could be pound-for-pound the world's strongest human. But did his parents completely cross the line in helping Richard reach his full potential in becoming a body-building champion? ABC News correspondent Bill Ritter talks to Richard, now 12, about the sacrifices he made along the way, including having no friends, the around-the-clock workouts and even the speculation of being fed steroids by his father. The exclusive interview airs on "20/20," FRIDAY, MARCH 11 (10:00-11:00 p.m., ET) on the ABC Television Network.

Also: Last year the graphic pictures of the Americans' bodies hanging from a bridge in Fallujah shocked the public. A year after their civilian sons were killed by Iraqi insurgents, two mothers of the ambushed contractors speak out in search of the truth about the brutal deaths. Katy Helvenston-Wettengel, mother of Scott Helvenston, and Donna Zovko, mother of Jerry Zovko, speak exclusively to ABC News Chief Investigative Correspondent Brian Ross about how Blackwater, the private military company that employed their sons, has refused to divulge the results of the company's own investigation concerning the circumstances under which the young men were killed. Helvenston-Wettengel says her son was sent into Iraq with poor armor and poor training, a result of what she calls corporate greed and incompetence. Blackwater officials have refused to comment for this report, but in previous press statements said their men were victims of a well planned ambush.

And: "The Gates," a massive project in Central Park over the past few weeks, have prompted people to ask "what is art?," and have gotten John Stossel thinking - do people really know what art is? "20/20" mixed reproductions of famous abstract art, two pieces bought at a thrift store and paintings by four-year-olds to see if people could tell the difference between a "masterpiece" that costs millions of dollars and the painting of a pre-schooler.

"20/20" is anchored by Elizabeth Vargas and John Stossel. David Sloan is the executive producer.