NBC’s Brian Williams spent just three hours in London yesterday and then ditched the royal wedding to fly back to the US to cover the killer tornadoes in the South. Williams didn’t even leave Heathrow after he landed and heard about the extent of the devastation. A source told us, “He immediately called Steve Capus at NBC News and said he needed to be back in the US. NBC tried to fly him straight to Tuscaloosa, but couldn’t do it. He went straight back to New York three hours later to anchor the ‘Nightly News’ from there” before heading to Alabama. The source predicted that Williams’ move will leave rival anchors still in London “fuming.”