An explosion occurred at the Midtown building that houses News corporation businesses including Fox News and the NY Post. Fox 5 reports that a man was burned in the chemical explosion and 700 people have been evacuated. However, "the explosion has not interrupted the cable news channel's broadcast."
1211 Avenue of the Americas is partly owned by the Rockefeller Group Development Corporation. It was opened in 1973 and is a "1.9 million square foot Class-A office building," with 45 stories.
In the Post's story about the explosion, so far it does not mention that the building is where its operations, as well as those of other Fox entities, are located.
Update: The Post now reports the explosion occurred in their building - the tabloid is on the 10th floor and the 41st, 42nd and 43rd floors were evacuated. Gawker received an internal memo that suggested the explosion was "POSSIBLY CAUSED BY OXIDIZERS REACTING WITH ACID." The explosion was in the mechanic room on the 45th floor of the building and could have involved 30 gallons of chemicals. 700 people were evacuated from the three floors below the explosion.