"Here's a movie with no terrorists, no guns, in which the world--that is, the environment of the tunnel--is the jeopardy," Daylight director Rob Cohen notes. For cast and crew alike, the tunnel as adversary made itself felt even beyond the script, as a grueling shooting schedule with up to 14-hour days took its toll. Fully 70 percent of the shoot took place in the specially constructed, 1/3 mile long tunnel set. "The physical conditions under which we worked in the tunnel were a whole other matter," Sylvester Stallone recalls. "Everyone there was pushed to their physical limits. The tunnel itself became a real psychological and physical testing ground for everyone's nerve and verve." It wasn't imaginary. Real dangers lurked, creating an atmosphere of risk that never entirely disappeared. Following a potentially dangerous gas leak that forced a halt to production and evacuation of the tunnel, Cohen recalls, "It was a weird feeling evacuating everyone, like deja vu since I had imagined something like that happening so many times." Cohen also had to contend with the Venturi Effect, that physical phenomenon whereby a fire or explosion will actually seek an oxygen source. "The Venturi Effect is what causes the explosion in the movie to be so devastating, turning from the sealed off Jersey entrance back to the Manhattan entrance," he says. "There was always the danger of our effects explosions and fires getting out of control. We were very, very careful." No serious incidents or accidents marred the production, due in no small part to the care taken to make everything right with the tunnel. Tunnel logistics, in fact, even played a part in the decision to shoot Daylight at Rome's Cinecitta Studios, according to executive producer Raffaella De Laurentiis. After a thorough search that covered both the U.S. and Europe, Cinecitta was selected "because of the size of the studio and its backlot," De Laurentiis explains. "It had this huge, flat area where we built the tunnel and a hill above where we built the entrance. There were 16 tanks which we needed so the sets could be flooded, and there was a huge pool that served as our water reservoir. Logistically, the studio was perfect." The same thoroughness and attention to detail extended to the construction of the tunnel, a monumental task considering the demands that would be made on it. "It had to be built as a real tunnel," De Laurentiis notes, "because cars were going to travel through it and big stunts were going to happen there. Naturally, it also had to function as a movie set, so we had to have extra entrances and exits for security and safety, plus a ventilation system." "It was very difficult to imagine how to put the world of the plot on the screen," production designer Benjamin Fernandez (Dragonheart, 1492: Conquest of Paradise) adds, "especially because of the special effects requirements caused by the number of calamities and stunts taking place, to be executed by special effects supervisor Kit West." West, who won an Academy Award for his work on Raiders of the Lost Ark, had the challenging job of bringing a variety of frightening disasters to spectacular life for Daylight, including the devastating explosion that sets the scene and stretches out for more than two on-screen minutes, as both ends of the tunnel are collapsed, the Mid-River Tower eruption and the blast "plasma" which engulfs everyone and everything inside as it races from Jersey to Manhattan. "It was a new way to depict a very complex event," Cohen reveals. "We used a combination of on-set effects, miniatures and computer graphics to provide a very detailed look inside the explosion. Over 60 editing cuts, and no slow motion, give a two-minute look at something that would only take seconds in real life." Latura's entry into the tunnel via the ventilation fans provides another gripping sequence that was as frightening to create as it is to view. "The fans are 18 feet in diameter, and the whole structure is over 80 feet high," Cohen explains. "It was very difficult to shoot, very nerve-wracking. It was like shooting in a giant cuisinart." For a few of the most complex sequences, the filmmakers also engaged the special effects wizards at Industrial Light & Magic, who had just previously collaborated with Cohen and De Laurentiis in creating Dragonheart's dragon, in addition to the dinosaurs of Jurassic Park and the tornadoes in Twister. "We were involved in two parts of the film, the explosion that collapses the tunnel in the beginning and the `blowout' at the end," recalls Scott Farrar, ILM's Oscar-winning Visual Effects Supervisor. From the initial explosion of the toxic waste truck to the final sealing off of the Manhattan entrance, the ILM crew worked its magic, combining miniatures, computer graphics and on-set shots. "Our first priority was to make sure that there was no question that the superheated fire could close off the tunnel. That was a must," according to Farrar. One of the most interesting techniques used by Farrar was the construction of a 1/4-scale replica of the actual tunnel set. This proved most useful in depicting the fast-moving nature of the explosion and the resulting superheated waves of flame. "We had a very complicated articulated plumbing system in our scale tunnel," Farrar explains. "This was because, on such a small scale, everything moves much faster. We had individual gas jets timed down to 1/500th of a second! We needed a mini-computer just to handle the speed and sequencing. We were micro-managing the flames, so to speak."