Baltimore Key Bridge collapse: Controlled demolition scheduled for Monday

Collapsed Baltimore Key Bridge span comes down with a boom

Leaders in Baltimore are one step closer to reopening the channel – after the tragic collapse of the Key Bridge back in March - that killed six construction workers. An explosion was set off early this evening to help remove the cargo ship that’s sitting on the water. FOX 5’s Nana-Sentuo Bonsu is in Baltimore with more.

BALTIMORE - Crews conducted a controlled demolition Monday evening to break down the largest remaining steel span of the collapsed Francis Scott Key Bridge in Baltimore.

The explosives flashed orange and let off a cloud of black smoke upon detonation, and the span crumpled into the water in seconds. The longest trusses toppled away from the grounded Dali container ship and slid off its bow.

It marked a major step in freeing the ship, which has been stuck amid the wreckage since it lost power and crashed into one of the bridge’s support columns shortly after leaving Baltimore on March 26. The demolished span came crashing down on the ship’s bow and remained resting on its deck for the past six weeks.

Engineers have been preparing for weeks to use explosives to break down the span, which is an estimated 500 feet (152 meters) long and weighs up to 600 tons (544 metric tons). It landed on the ship’s bow after the Dali lost power and crashed into one of the bridge’s support columns shortly after leaving the Port of Baltimore. Since then, the ship has been stuck amidst the wreckage and the port has been closed to most maritime traffic.

The controlled demolition of the largest remaining steel span of the collapsed Francis Scott Key Bridge in Baltimore was postponed because of weather conditions, officials said Sunday afternoon.

"This is a best practice," Gov. Wes Moore said at a news conference Monday. "Safety in this operation is our top priority."

Moore noted that there have been no injuries during the cleanup and that the controlled demolition will allow crews to maintain a strong safety record.

Engineers are using precision cuts to control how the trusses break down, causing them to fall away from the Dali when explosives send them tumbling into the water, officials said. Once it’s demolished, hydraulic grabbers will lift the broken sections of steel onto barges.

WATCH: Baltimore Key Bridge explosion

Crews conducted a controlled demolition Monday evening to break down the largest remaining steel span of the collapsed Francis Scott Key Bridge in Baltimore, a major step in the cleanup as officials seek to fully reopen the port’s busy shipping channel by the end of the month.

Six members of a roadwork crew plunged to their deaths in the March 26 collapse. The last of their bodies was recovered from the underwater wreckage last week. All the victims were Latino immigrants who came to the U.S. for job opportunities. They were filling potholes on an overnight shift when the bridge was destroyed.

The controlled demolition will allow the Dali to be refloated and guided back into the Port of Baltimore. Once the ship is removed, maritime traffic can begin returning to normal, which will provide relief for thousands of longshoremen, truckers and small business owners who have seen their jobs impacted by the closure.

It landed on the ship’s bow after the Dali lost power and crashed into one of the bridge’s support columns shortly after leaving Baltimore. Since then, the ship has been stuck amidst the wreckage and Baltimore’s busy port has been closed to most maritime traffic.

The Dali’s 21-member crew will stay onboard the ship while the explosives are detonated.

William Marks, a spokesperson for the crew, said they would shelter "in a designated safe place" during the demolition. "All precautions are being taken to ensure everyone’s safety," he said in an email.

Officials said the demolition is the safest and most efficient way to remove steel under a high level of pressure and tension.

"It’s unsafe for the workers to be on or in the immediate vicinity of the bridge truss for those final cuts," officials said in a news release Sunday.

Part of Baltimore Key Bridge collapses in explosive demolition

The controlled demolition to remove part of the Baltimore Key Bridge from the stranded Dali ship in the Patapsco River is complete. FOX 5's David Kaplan spoke with Colonel Estee Pinchasin with the Army Corps of Engineers about the explosive mission.

In a videographic released last week, authorities said engineers are using precision cuts to control how the trusses break down. They said the method allows for "surgical precision" and the steel structure will be "thrust away from the Dali" when the explosives send it tumbling into the water.

Once it’s demolished, hydraulic grabbers will lift the resulting sections of steel onto barges.

"It’s important to note that this controlled demolition is not like what you would see in a movie," the video says, noting that from a distance it will sound like fireworks or loud thunder and give off puffs of smoke.

So far, about 6,000 tons (5,443 metric tons) of steel and concrete have been removed from the collapse site. Officials estimate the total amount of wreckage at 50,000 tons (45,359 metric tons), about the equivalent of 3,800 loaded dump trucks.

Officials previously said they hoped to remove the Dali by May 10 and reopen the port’s 50-foot (15.2-meter) main channel by the end of May.

The Dali is currently scheduled to be refloated during high tide on Tuesday, officials said Sunday. They said three or four tugboats will be used to guide the ship to a nearby terminal in the Port of Baltimore. It will likely remain there for a few weeks and undergo temporary repairs before being moved to a shipyard for more substantial repairs.

The Dali crew members haven’t been allowed to leave the vessel since the disaster. Officials said they have been busy maintaining the ship and assisting investigators. Of the crew members, 20 are from India and one is Sri Lankan.

The National Transportation Safety Board and the FBI are conducting investigations into the bridge collapse.

Danish shipping giant Maersk chartered the Dali for a planned trip from Baltimore to Sri Lanka, but the ship didn’t get far. Its crew sent a mayday call saying they had lost power and had no control of the steering system. Minutes later, the ship rammed into the bridge.

Officials have said the safety board investigation will focus on the ship’s electrical system.