Fox News Channel was the most-watched network yesterday morning during the breaking news of the explosion in Harlem, NY, both total viewers and in the news demo. At 10 AM ET, when reports of an explosion demolishing a building first broke, Fox News delivered 1.31 million total viewers — more than CNN (670,000) and MSNBC (313,000) combined — and 297,000 demo viewers (to CNN’s 201,000 and MSNBC’s 109,000). Fox News jumped 42% in the news demo in that hour, compared to the 209,000 viewers of one day earlier. CNN climbed 49% in the hour, but from a smaller base of 135,000 demo viewers at 10 AM Tuesday to 201,000 demo viewers when the blast became the headline. MSNBC, which tends not to draw a lot more viewers for breaking catastrophic news the way the other cable news networks do, went up a more modest 17%, up from the previous day’s 93,000 demo viewers to 109,000. Fox News also finished first for the total day in both overall audience and in the demo, though CNN’s AC360 clocked a rare demo win against The O’Reilly Factor at 8 PM with coverage of the latest twists in the missing Malaysia Airlines flight.