A piece of Bay Area history was blown to bits Saturday morning.
Pier E3 — the largest remaining pier of the old eastern span of the San Francisco-Oakland Bay Bridge — was leveled at 7:17 a.m. Demolition crews used 22,000 pounds or 600 charges of dynamite for the implosion, officials said.
The implosion did in six seconds what would have taken four years if done with machines and work crews. Nonetheless, those few seconds still represent two years of planning, a half dozen permits, and thousands of hours of labor from CalTrans and contractor Kiewit-Manson, who worked in tandem to complete the demolition.
"If we had come into the bay with a mechanical process, it would've cost $100 million more to do it," Caltrans spokeswoman Leah Robinson-Leach said.
Caltrans Implodes Old Bay Bridge Pier
Spectators, however, were unable to really get a chance to watch the implosion up close and personal, mostly because the entire ordeal was underwater. They saw little other than a blast of water heaved 100 feet into the air.
"This is not like Las Vegas, where you see an implosion and there's a huge visual," Robinson-Leach said. "This is not a tourist attraction. It's a demolition."
Environmentalists have been worried about how the blast will affect the wildlife, and a Caltrans official said that 1,800 long fin smelt will likely be killed.
Still, the plan called for a blast mat to contain dust, a bubble curtain to absorb shock and protect as many plants and marine animals as possible, and there's a hollow structure laid on the bay floor to collect debris.
The bubble curtain, made from holes drilled in underwater pipes, was designed uniquely for this demolition to keep away marine life. A large steel mesh was also in place on top of the pier to keep flying debris to a minimum.
Scientists also tried to make sure that two bird species, the endangered least tern and the protected brown pelican, were not in harm's way. If either dived within 500 feet of the pier, monitors pointed lasers and sounded off air horns to shoo the birds clear of the demolition.
The detonation was the marriage of engineering efficiency and environmental friendliness but environmentalist have still to determine whether the safeguards were successful.
"In the coming weeks, we’ll be exhaustively collecting extensive data and determining the effects the implosion had on the environment and fish nearby," said Bryan Maroney, chief bridge engineer of Caltrans’ Toll Bridge Program. "We don’t know exactly what it looks like down there, not yet."
Bay Bridge traffic was held for about 15 minutes to prevent potential distraction to drivers, and BART trains were temporarily stopped outside the Transbay Tube, prompting slight delays. Watercrafts on the bay were also kept at least 1,500 feet away.
The Bay Bridge demolition began in September 2013 and is scheduled to be completed in 2018. Caltrans must still remove 21 more piers. The old eastern span was built in 1936 but was damaged in the 1989 Loma Prieta earthquake.
NBC Bay Area's Chuck Coppola and Stephanie Chuang contributed to this report.