Fort Smith police are investigating an explosion outside a home that sent a woman to the hospital with severe leg injuries. Police said the woman found the device in front of a vacant home. The woman, who police did NOT identify, apparently was taking the device across the street to a friend`s house when it detonated. Police Sergeant Jarrard Copeland says officers searched the neighborhood for other suspicious packages or devices. The police, the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives are on the scene and closed off the area around the home. Copeland says Arkansas State Police and Springdale police could be involved, too, because they have bombs squads. Copeland said the woman is the caretaker of the vacant residence.