Your daily news recap: Koreas, the Dow and the death of a state trooper

North Korea, South Korea reach agreement

North Korea and South Korea have reached an agreement to de-escalate tensions on the Korean Peninsula, South Korean National Security Chief Kim Kwan-jin announced.
South Korea will get the apology it demanded over recent military escalation by the North, and South Korea will stop broadcasting propaganda that infuriated the North.

    Market takes a wild ride

    After an unprecedented 1,000-point decline at the open on Monday, the Dow closed with a loss of nearly 600 points.
    It was an extremely turbulent day for U.S. stocks driven by deep fears about China's economic slowdown. Stocks staged a comeback that nearly brought the Dow back into positive territory but that ultimately failed.
    The 588-point decline was the worst for the Dow since August 2011.

    Trooper shot, killed after stopping to help

    Authorities in Louisiana are working to connect the possible dots between two killings -- that of Louisiana State Trooper Steven Vincent and another man, who officials have not yet named.
    The second victim was believed to have been sharing a home with Kevin Daigle, 54, who authorities say has been charged in Vincent's death.
    The 44-year-old veteran trooper was shot Sunday after he stopped to help Daigle, whose pickup was stuck in a ditch, according to Col. Michael Edmonson, the police force's superintendent. Vincent died of his injuries Monday.