that deadly police standoff, officers called to this home, both officers shot. and tonight, we have now learned what they thought they were responding to. the beloved high school principal who died after donating bone marrow to a boy. how does this happen? your money tonight. gas prices on the rise. and where it's already topping $4. and tonight, the new report. the best day to buy gas and the worst. one of the great mysteries tonight. astronomers now revealing the first image of a black hole. and a nation riveted. he was one of the most famous tv contestants, watched by millions. back in the news tonight. good evening. and it's great to have you with us here on a wednesday night. and we are tracking that major blizzard on the move tonight. 20 states, 1,000 flights affected. but we do begin tonight with that horrific scene in durham, north carolina, a massive explosion. it happened after a call about a gas leak near downtown, a downtown building, in fact.