 In 1929, Sir Winston Churchill visited the building and made his first transatlantic telephone call, phoning his London home.For 44 years until 1978, the top of the roof was used to convey official storm warnings to sailors at the direction of the United States National Weather Service, in the form of a long triangular red flag by day, and a red light at night.In 2007, the PacBell Building was sold by AT&T to Stockbridge Capital Group and Wilson Meany Sullivan for .