Gov. Brad Henry today declared a state of emergency for 17 Oklahoma counties that were affected by Tuesday's tornadoes. A tornado in the Carter County town of Lone Grove killed eight people and injured dozens more, state officials said. Tornadoes also caused extensive damage in several Oklahoma communities, including Edmond, Oklahoma City, Pawnee, Wilson and Springer. The counties in the governor's declaration are: Canadian, Carter, Cleveland, Garvin, Jefferson, Lincoln, Logan, Love, Murray, Oklahoma, Pawnee, Payne, Pontotoc, Pottawatomie, Nowata, Osage and Washington. More counties can be added if conditions warrant. Henry said state officials are ready to provide eligible assistance. “The state of emergency declaration strengthens our efforts to help those areas, but it also serves as a first step toward seeking federal assistance," Henry said. Under the declaration, state agencies are allowed to make emergency purchases and acquisitions needed to expedite the response to the disaster.