In the United States, a helicopter used for inspecting power lines has crashed into a snowy Ohio field, killing the two men on board. It's not clear what caused the crash today just south of the Ohio Turnpike in Wood County. <br/><br/>Sheriff Mark Wasylyshyn said there was no sign of fire and no indication that the aircraft hit any utility lines.The Federal Aviation Administration and the National Transportation Safety Board were expected to send investigators to the scene.<br/><br/>