The Gulf Tower is a 44-story, Art Deco skyscraper in downtown Pittsburgh, Pennsylvania. The tower is one of the major distinctive and recognizable features of the city and is named for the Gulf Oil Corporation, one of the leading multinational oil companies of its time, and one of the Seven Sisters of the Anglo-American oil industry prior to its merger with fellow oil giant Chevron. Built as the headquarters for the Gulf Oil Company, the structure was designed by the firm of Trowbridge & Livingston and completed in 1932 at a cost of $10.05 million ($ million today). As late as 1981 Gulf Oil employed 3,100 within the building. Now called Gulf Tower, it has 44 floors and rises above Downtown Pittsburgh. The crown of the skyscraper is modeled after the Mausoleum of Halicarnassus in the style of a step pyramid. The building was listed as a Pittsburgh History & Landmarks Foundation Historic Landmark in 1973. On June 13, 1974, a bomb was detonated on the 29th floor of the Gulf Tower. The Weather Underground Organization took credit for the attack, claiming it was in protest to Gulf Oil's involvement in the oil rich regions affected by the Angolan War of Independence. The building was condemned following a fire on May 19, 2021 and required repairs. The Gulf Tower reopened to tenants and visitors six months later. Lighting Prior to the late 1970s, the entire multistory "step-pyramid/mausoleum" structure at the top of the building was neon-illuminated, changing colors to provide a weather forecast that could be seen for many miles. This concept was developed by the building manager Edward H. Heath. He used the Gulf Oil colors to create a simplified forecast: steady blue meant colder and fair; flashing blue meant colder with precipitation; steady orange meant warmer and fair; flashing orange meant warmer with precipitation. Subsequently, in an effort to conserve energy, the weather forecasting role had been limited to the weather beacon at the pinnacle of the pyramid, which would glow blue for precipitation and red for fair weather. Although the terraced sides were once again illuminated at night (by means of spotlights), the entire pyramid structure no longer changed color with the weather (the pinnacle beacon still had that function). Since 2001, the opening of PNC Park across the Allegheny River, fans have noticed that after Pittsburgh Pirates home-runs, the "beam" light flashes in celebration. Recently it