1 dead, 1 hurt in Nev. tunnel collapse One construction worker was killed and one was injured Monday when an under-construction tunnel collapsed near Lake Mead, Nev., the National Park Service said. LAKE MEAD, Nev., June 11 (UPI) -- One construction worker was killed and one was injured Monday when an under-construction tunnel collapsed near Lake Mead, Nev., the National Park Service said. There had been a report 18 workers were trapped and at least 25 were exposed to toxic gases when the tunnel collapsed, but Scott Huntley, a spokesman for the Southern Nevada Water Authority said the reports were unfunded, KLAS-TV, Las Vegas, reported. Huntley said a tunnel ring the crew had been working on came loose and made contact with grout material that was highly pressured. The grout struck two workers, killing one and injuring the other. Other workers evacuated the work site unharmed, KLAS reported. The tunnel is one of several being constructed by the Nevada Water Authority -- collapsed, KVVU-TV, Las Vegas, reported.