"None of them saw this coming," a source inside CBS3 said Wednesday of the firings.
May had "some time left" on his contract, the source said.
Argentina was selected as host, largely because it was the only country willing to take on the task.
The world championship has been held every four years since the inaugural tournament in 1950, except for two occasions.
Washington, who will start in the new role July 13, will be joined by Jessica Dean, who is currently a co-anchor. CBS3 disclosed the new team a day after the station's general manager, Brien Kennedy, fired three of his top TV news personalities: nighttime anchor Chris May, meteorologist Kathy Orr, and sports anchor Beasley Reece.
CBS3's group firing of May, Orr and Reece on Tuesday appears unprecedented in recent times for a Philadelphia TV station, and occurred only hours before the anchors were to appear on camera.
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