Television's most powerful moments
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Osama bin Laden
- 2/19
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Challenger
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Osama bin Laden
- 6/19
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- 9/19
Oil spill
- 10/19
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- 11/19
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Casey Anthony
- 19/19
Nielsen ratings
According to a new study released by Nielsen, the Sept. 11 terrorist attacks, Hurricane Katrina and the O.J. Simpson verdict were among the most "impactful" moments in television history. Here are some of them.