Investigators probing the death of "Top Gun" director Tony Scott said they still don't know why he plunged from the Vincent Thomas Bridge on Sunday. 
 
 Law enforcement sources said several notes Scott left do not mention any health problems or offer solid clues about why he jumped. It's possible, the sources said, that authorities might never make a clear determination of motive. 
 
 An autopsy was performed Monday. But, as in many cases, the coroner said a final cause of death would not be determined until toxicology and other test results became available in several weeks. 
 
 Officials have not determined whether Scott had any health problems before he jumped off the San Pedro bridge but said family members have denied media reports that he was suffering from cancer. 
 
 "The family told us it is incorrect that he has inoperable brain cancer," said Craig Harvey, a chief with the coroner's office. 
 
 Several people who were driving over the bridge when Scott jumped described witnessing what happened. 
 
 "He was on the roadway close to the fence looking around. He was looking around and fumbling with something at his feet. He looked nervous," David Silva told The Times. 
 
 Silva said he was a passenger in a car on the north side of the bridge and Scott was on the south side. 
 
 Silva said Scott "paused a couple of seconds and then began to climb the fence. He put his foot on the top of the fence and paused again. And then he threw himself off. I immediately thought, that guy is dead." 
 
 At first, Silva and other motorists thought the jump was an extreme-sports stunt. Then they realized the jumper didn't have a parachute or safety cord. 
 
 Silva said he called 911 immediately. 
 
 A Rancho Palos Verdes man who was driving across the bridge said the director appeared "determined" and "resolute." 
 
 Eric Brill, 59, said he was returning home after visiting his mother in Laguna Woods when he spotted a man wearing multicolored clothing climbing one of the cables on the other side of the bridge. The man was "clambering up in a very strong way," Brill said, something that confused him until he read later that Scott was an avid rock climber. 
 
 "It takes a while to register in your brain, because you're not used to seeing anything like this and for a few seconds you think it's some kind of mistake," Brill said. "I looked more closely — perhaps it's a maintenance man. But I knew very soon after that it wasn't anyone doing maintenance." 
 
 As Brill was about to drive past Scott, he said, the director "turned around, as if to see if someone was after him." 
 
 "I could very, very clearly see his face," Brill said. "He was very determined. He was not crying, he didn't look upset, he didn't look sad. He just looked very resolute." 
 
 Brill said he had read accounts from witnesses describing him as nervous and fidgety. 
 
 "I didn't see that," Brill said. "What I saw was a very determined guy." 
 
 richard.winton@latimes.com 
 
 kate.mather@latimes.com ||||| Reshoots for "Unstoppable" were filmed at the site; the director also said in 2009 that he wanted a shot on the span for a planned "Warriors" remake. 
 
 This story first appeared in the Aug. 23-Sept. 5 issue of The Hollywood Reporter magazine. 
 
 The bridge that Tony Scott leaped from Aug. 19 is a Los Angeles-area landmark that featured in the director's storied career -- playing a part in a past success and a potential future project. It was at a railroad yard beneath the 185-foot-high connector between San Pedro and Terminal Island that the British director-producer filmed reshoots of his 2010 Denzel Washington hit Unstoppable. And in 2009, Scott told Rotten Tomatoes he wanted to shoot a sequence of his planned remake of The Warriors at the location. "I'm hoping to get 100,000 real gang members standing on the Vincent Thomas Bridge for one shot," he told the movie news site in June 2009. 
 
 PHOTOS: Tony Scott's Films: From 'Top Gun' to 'Unstoppable' 
 
 Instead, the 68-year-old filmmaker's tragic end has been deemed "a witnessed suicide" by authorities, shocking the entertainment industry as conflicting reports about his health in recent months continue to muddy any clear sense of why he would kill himself. 
 
 According to police investigators, the Top Gun and True Romance director, the younger brother of filmmaker Ridley Scott, parked his Toyota Prius on the suspension bridge and scaled an 18-foot fence at about 12:30 p.m. before throwing himself into Los Angeles Harbor. The Los Angeles Times reported that detailed contact information found inside Scott's car led authorities to a suicide note in his office at Scott Free Productions, the prolific film and TV company he ran with his brother. 
 
 While the basic outline of Scott's final moments is clear, the reasons behind his actions remain shrouded in mystery. An Aug. 20 report by ABC News said that Scott, whose films include Crimson Tide, Days of Thunder and Man on Fire, suffered from inoperable brain cancer. But Los Angeles County Coroner's chief investigator Craig Harvey said later that day that the director's family -- Scott was the father of twin preteen boys with wife Donna Wilson Scott -- told investigators it was "incorrect" that the filmmaker had brain cancer. ABC News, which drew widespread media scrutiny, later amended its story to say Scott's family was unaware he had cancer. (An ABC News rep tells THR it is continuing to pursue the story and "will issue a full retraction and apology" if incorrect information was reported.) An autopsy conducted Aug. 20 could shed light on any Scott health problems. Ed Winter, assistant chief of investigation for the coroner's office, says that his office does not yet know if Scott was ill. (Any pre-existing ailments likely won't be determined for several weeks, once toxicology and other test results are returned.) Scott's publicist, Simon Halls, did not respond to e-mails and phone calls seeking comment about his client's health. 
 
 STORY: Tony Scott's Death: Witness Says Director Was 'Determined' Just Before Jumping From Bridge 
 
 Scott -- a former commercials director who came to prominence in Hollywood with 1986's Top Gun -- was as busy as ever. The hard-charging filmmaker known for his worn-out red hat and penchant for cigars often juggled several projects at the same time. "He had so much on the go," says a producer who worked with him. "That's why this is so shocking." 
 
 After this summer's hit Prometheus, which he produced and Ridley directed, Scott had several high-profile projects in development. As late as Aug. 17, Scott met with Tom Cruise to research their planned Top Gun sequel for Paramount. According a source close to the project, the pair were in Nevada touring a naval air station. "Tony was my dear friend, and I will really miss him," said Cruise in a statement. He and Scott also worked together on the 1990 NASCAR thriller Days of Thunder. "He was a creative visionary whose mark on film is immeasurable." 
 
 STORY: Tony Scott Spent Final Days Working With Tom Cruise on 'Top Gun 2' 
 
 Before the Top Gun sequel, Scott was expected to direct Narco Sub, which centers on a disgraced U.S. naval officer forced to pilot a submarine carrying a payload of cocaine to America, for 20th Century Fox. Scott Free has its production deal at Fox, which recently tapped writer Jeffrey Nachmanoff (Traitor) to rewrite the script. Another project, the mob thriller Potsdamer Platz, had Mickey Rourke attached, and Scott was prepping Lucky Strike, an $80 million project set in the world of jet repossession, with Vince Vaughn and Emmett/Furla Films. The status of those movies is unclear, but Scott's final completed project, an A&E miniseries called Coma that he executive produced, is scheduled to premiere on Labor Day. 
 
 Borys Kit and Pamela McClintock contributed to this report. 
 
 Email: Daniel.Miller@THR.com 
 
 Twitter: @DanielNMiller
– The reason that drove Tony Scott to leap to his death from an LA bridge may never be known. Law enforcement sources tell the LA Times that the director left a few notes, but none of them give any motive for the suicide, including health problems. A witness who was driving across the bridge when Scott jumped says the director, a rock climber, was "clambering up [the bridge cables] in a very strong way. … He was very determined. He was not crying, he didn't look upset, he didn't look sad. He just looked very resolute." Scott had filmed parts of Unstoppable underneath the very same bridge, and in 2009 the director said he wanted to shoot part of a Warriors remake there, according to the Hollywood Reporter. The Reporter also has previously unpublished quotes from an interview it did with Scott in May, in which he called himself "a bull" and said that work was his "drug of choice." A friend of Scott's told NBC News that the director struggled with depression "throughout his life," E! reports.