Defunct Martin Tower, former world HQ of Bethlehem Steel, demolished

BETHLEHEM, Pa. (AP) — Sixteen thousand tons of Bethlehem Steel collapsed in a matter of seconds Sunday as a demolition crew imploded Martin Tower, the defunct steelmaker's former world headquarters.

Crowds gathered to watch the demolition of the area's tallest building, a 21-story monolith that opened at the height of Bethlehem Steel's power and profitability but had stood vacant for a dozen years after America's second-largest steelmaker went out of business.

Explosives took out Martin Tower's steel supports and crumpled the 47-year-old building, which had earned a spot on the National Register of Historic Places despite its relatively young age. The implosion created a dust plume expected to linger for several minutes before settling to the ground.

Martin Tower's current owners spent years trying to redevelop the 332-foot (101-meter) structure — the tallest in a heavily populated region that includes the cities of Allentown, Bethlehem and Easton — but ultimately concluded it made more economic sense to knock it down and start over. Plans call for a $200 million development with medical offices, retail stores, a restaurant, a convenience store, a hotel and 528 apartments.

Bethlehem Steel was a major supplier of ships and armaments to the U.S. military during World War II, and its steel is found in the Empire State Building, the Golden Gate Bridge and many other landmarks.

The company moved into its new corporate headquarters in 1972, shortly before the U.S. steel industry plunged into a severe recession. Bethlehem Steel, which employed more than 120,000 people when Martin Tower opened, declared bankruptcy in 2001 and closed for good two years later.

The company’s historic Bethlehem mill, less than 2 miles (3 kilometers) from Martin Tower, was redeveloped into a casino and entertainment destination 10 years ago.