OCRACOKE, N.C. (AP)  Five people working on Independence Day fireworks shows were killed by explosions, four of them by a single blast that rocked this remote village on the Outer Banks. The fifth died after an explosion at a fireworks show in Pennsylvania, police said. In another holiday accident, a pedestrian bridge collapsed in Indiana as fans were leaving a fireworks show, injuring 25 people. Authorities said Sunday the crowd had overloaded the bridge. The blast at Ocracoke came as workers were unloading fireworks Saturday from a truck at the Anchorage Marina, shaking homes and businesses across the southern end of Ocracoke Island and rattling residents and tourists. Earl Woodham, a spokesman for the Bureau of Alcohol, Tobacco, Firearms and Explosives, said agents determined the cause was accidental. ATF will not investigate further, but a workplace safety agency such as the state Labor Department likely will try to find the specific cause, he said. Dock master Robert Raborn was about 200 yards away from the truck and said the explosion was one of the loudest things he had ever heard. "It was like 40 minutes worth of fireworks going off in four seconds," Raborn said. One of the workers died at the scene Saturday and three others died later at area hospitals, including one who died on Sunday, said Hyde County spokeswoman Jamie Tunnell. Another person was listed in fair condition at the North Carolina Jaycee Burn Center at the UNC Medical Center in Chapel Hill. The Ocracoke victims worked for Melrose South Pyrotechnics near Rock Hill, S.C. The company said it had sent a representative to work with investigators. Meanwhile, a silent parade was held Sunday in tribute to the victims and the people who responded to the explosion, following the intended route of Saturday's Independence Day parade. In Pennsylvania, state police fire marshals were investigating the death of a worker Saturday at the start of the grand finale of fireworks at Quakertown's Memorial Park. Quakertown Police Chief Scott McElree said authorities immediately halted the show and evacuated part of the park in eastern Pennsylvania. Authorities did not immediately identify the man's employer. At Merrillville, Ind., the collapse of a wooden pedestrian bridge dropped at least 50 people into a lake Saturday night and injured about half of them, police said. None of the injuries was life-threatening, authorities said. The collapse occurred at Hidden Lake Park in Merrillville, about 45 miles southeast of Chicago, as spectators were leaving a fireworks display at about 10 p.m. The wooden, cable-suspended bridge could support about 40 people at a time but as many as 80 were on it when it gave way, said Ross Township Trustee John Rooda, who attended the fireworks show. The township operates the park. "The problem is it was overloaded," Rooda said. In Albuquerque, a man watching a fireworks show was killed by lightning from a thunderstorm Saturday evening and his wife was also injured, police said. Names of the victims were not released and authorities said the woman was listed in stable condition at a hospital. And in Missoula, Mont., an 8-year-old girl was accidentally electrocuted and two other children were injured while watching a fireworks show Saturday night from a church rooftop. Missoula County Sheriff Mike McMeekin said the children had climbed on some air-conditioning equipment. Home fireworks shows also proved dangerous. In Wisconsin, Jefferson County Sheriff Paul Milbrath said a 12-year-old boy suffered a head injury when he was hit by one of the pyrotechnics fired at a July Fourth party. The boy was taken to a hospital in Milwaukee. His name and condition weren't released. The Callahan Eye Foundation Hospital in Birmingham, Ala., treated five patients who were hurt in fireworks accidents, spokeswoman Gail Short said Sunday. Flames from fireworks damaged at least seven homes in western Washington state and destroyed some ranch housing near Harrah on the Yakama Indian Reservation, causing more than $2 million in damage, authorities said. Copyright 2009 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more