Sheriff: 'There's much work to be done'

This image provided by Logan Messerly shows ambulances on the scene at Canandaigua Motorsports Park on Saturday Aug. 9, 2014 in Canandaigua, N.Y. Authorities are investigating a serious crash that injured one person at a New York dirt track where Tony Stewart was racing on the eve of a NASCAR race. (AP Photo/Logan Messerly)
This image provided by Logan Messerly shows ambulances on the scene at Canandaigua Motorsports Park on Saturday Aug. 9, 2014 in Canandaigua, N.Y. Authorities are investigating a serious crash that injured one person at a New York dirt track where Tony Stewart was racing on the eve of a NASCAR race. (AP Photo/Logan Messerly)

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    Sheriff: 'There's much work to be done'

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Ontario County Sheriff Philip C. Povero says there is a lot of work to be done in the Tony Stewart crash investigation.