A KEY WITNESS IN THE KOBE BRYANT CASE FINALLY BREAKS HIS SILENCE IN AN EXCLUSIVE "PRIMETIME LIVE" INTERVIEW WITH CYNTHIA McFADDEN, THURSDAY, APRIL 7 ON ABC

Also: Young Surfing Star Bethany Hamilton on Her Inspiring Return to Competition After Losing an Arm in a Shark Attack

And: Exclusive Interviews with the Mothers of Two Contractors Murdered and Mutilated in Fallujah, Still Asking for Answers

In an exclusive interview with "Primetime Live's" Cynthia McFadden, a key witness in the Kobe Bryant case speaks out for the first time about what the accuser told him at the time of the incident. With Bryant and his accuser both gagged as a condition of their civil settlement, Bob Pietrack is perhaps the closest person to the case who is allowed to talk. Pietrack was on duty as a bellman at the Edwards, CO, hotel on the fateful night Bryant checked in. He provides a detailed chronology of events -- including what Bryant's accuser said happened in the NBA star's hotel room. McFadden asks Pietrack whether he believes the accuser's account and if he is disappointed that she decided to drop the criminal suit against Bryant. He addresses reports that he had a sexual relationship with the accuser prior to the alleged assault and that she has now severed all ties to him. The "Primetime" report also features never-before-heard portions of the tape of Bryant's police interview. "Primetime Live" airs THURSDAY, APRIL 7 (10:00-11:00 p.m., ET) on the ABC Television Network.

Also: Bethany Hamilton made worldwide headlines after she lost her arm - and nearly her life -- in a vicious shark attack while surfing off the coast of Kauai, Hawaii. She has been widely lauded for her bravery and positive attitude, yet most doubted this former surfing prodigy would ever surf competitively again. But Hamilton quickly got back on her board and has proven that she can still compete with the best in her sport. Because of her courage, she has received numerous awards and even product endorsements. She tells Chris Cuomo why she refused to let her story become a tragedy, and explains her determination to live her dream -- as well as some she never could have imagined.

And: A year after their civilian sons were killed by Iraqi insurgents in Fallujah -- and the graphic pictures of the Americans' mutilated bodies hanging from a bridge shocked the public -- 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 allegedly 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 insufficiently trained and was sent out in an inadequately armored car, a result of what she calls corporate greed and incompetence. Blackwater officials refused to comment for this report, but in previous press statements said the men were victims of a well-planned ambush.

Diane Sawyer, Chris Cuomo, Cynthia McFadden and John Quiqones are the anchors of "Primetime Live." David Sloan is the executive producer.