May 19 (UPI) -- The 21-story Martin Tower, which was the former world headquarters of Bethlehem Steel, was imploded Sunday morning as bystanders lined the streets of Bethlehem and gathered on rooftops.
It took 14 seconds for the 332-foot tower -- the tallest in Bethelem -- to become a heap of debris, The Morning Call reported.
The 500 cubic yards of concrete and nearly 16,000 tons of structural steel collapsed at 7:04 a.m. from explosive charges.
On an overcast day, a series of bangs erupted within a half-second of each other and then there was a boom, like a strong thunderstorm.
Though the implosion took a short time, cleanup is expected to take up to a year. The concrete will be processed, crushed and used as fill material, and the structural steel recycled.
Spectators arrived hours earlier to watch the implosion. Customers Serita Dunst and Sean Wundling of Saylorsburg said they left home at 3 a.m. for a good viewing spot.
"When are you going to see something like this?" Wundling said.
Within a 1,000-foot perimeter of Martin Tower, people were advised to stay inside their residences.
Because a helicopter was flying too close and some people were crowding too near the exclusion zone, the demolition was delayed a few minutes.
"They weren't on the site but they were inside the established permitted zone," Mark Loizeaux, president of Controlled Demolition, Inc., told lehighvalleylive.com. "A few young people were hiding in the trees."
Controlled Demolition Inc., a 72-year-old Maryland company, brought down the building at an estimated estimated of $575,000. The company has imploded casinos in Las Vegas and Three Rivers Stadium in Pittsburgh.
"I'll shed a tear or two," said Steve Smith, who worked at Steel from 1966 to 2003 and described himself as "the last janitor at Martin Tower," told the Morning Call.
The building was on National Register of Historic Places.
Martin Tower opened in 1972 when Bethlehem Steel was the second largest steelmaker in the world. The building was named after Edmund F. Martin, who was chairman when construction began in 1969.
The company declared bankruptcy in 2001 and sold its assets in 2003.
After the company's assets were sold off, two tenants -- D&B Corp. and Receivable Management Services -- remained but they moved elsewhere in the Lehigh Valley in 2007. The tower was vacant ever since.
Owners Lewis Ronca and Norton Herrick plan to replace the tower with a mix of residential and commercial buildings that rise no higher than three stories on 53 acres.