US military says huge explosive the Navy set off to test new aircraft carrier didn't cause deadly condo collapse in Florida

• A condo in Florida collapsed six days after an explosive Navy test, raising questions.
• The military said the shock trials for its new carrier and the collapse are unrelated.
• Experts backed that view, saying there was no "reasonable" connection between the two incidents.
• See more stories on Insider's business page.

Questions have been raised about whether an explosive Navy test of its new aircraft carrier hundreds of miles away played a part in the deadly collapse of a condo in Miami six days later. The Pentagon and experts say it didn't.

On Friday, June 18, the Navy set off a 40,000 pound explosive in the Atlantic about 107 miles off the coast of Daytona Beach, Florida in shock trials for the new USS Gerald R. Ford aircraft carrier. The blast registered as a 3.9 on the Richter scale.

-USS Gerald R. Ford (CVN 78) (@Warship_78) June 20, 2021

Six days later, on June 24, Champlain Towers South, a 12-story condominium in Surfside, a Miami suburb over 250 miles away from the site of the Navy blast, partially collapsed. At least a dozen people have died, and more than one hundred people are still missing.

"I have seen nothing that will correlate the shock trial test with the terrible event today in South Florida," Pentagon press secretary John Kirby said last Thursday. "Certainly our thoughts and prayers go out to everybody affected by that."

The spokesman said that "we know we need to do this kind of testing for the whole of our major ships like aircraft carriers and that it's an important opportunity to evaluate the structural integrity of the hull and its ability to handle a blast of that size."

Kirby added that in choosing the location, "there's a lot of factors" that are considered "to make sure that it's as safe as it can possibly be."

Navy spokesman Capt. Clay Doss said in an emailed statement that "the USS Gerald R Ford (CVN 78) Full Ship Shock Trials (FSST) occurred approximately 100 [nautical miles] off of the coast of Jacksonville, Florida."

"There are no indications the tragic event in Miami is related to the test," he said. "During FSST, the Navy considers a wide variety of environmental and safety factors to protect people, vessels and wildlife in the surrounding area."

Paul Earle, a US Geological Survey National Earthquake Information Center seismologist, explained to the Miami Herald that the size of the explosion set off by the Navy, the distance from the condo collapse, and the time between the two incidents made any connection very unlikely.

"We do not see any reasonable mechanism for the Navy explosion on June 18 to have triggered the collapse of the Miami Beach-area condo on June 24," he said.

"There are about 300 earthquakes of similar size to the Navy explosion in the contiguous US every year, none of which have triggered a major building collapse," Earle said, adding that California sees 3.9 magnitude earthquakes regularly.

Florida-based building engineer Frederick Shaffer explained to the local news outlet WPTV that it was unlikely the Navy test impacted the building in Surfside, where buildings are built to withstand hurricanes.

"A building designed to South Florida standards should survive your average earthquake in California," he said.

A number of theories, ranging from foundation failures to construction damage, have been put forward, but for now, the cause of the deadly Surfside condo collapse remains unknown. And no single cause may be solely responsible for this tragedy.

Atorod Azizinamini, chair of the Department of Civil and Environmental Engineering at Florida International University, told The Miami Herald that disasters like this tend to be the result of "a perfect storm of several factors coming together at the same time."