Google made headlines a year ago putting mysterious barges near San Fransisco and Portland, Me., and then the barges suddenly disappeared — and the reason appears to be fire-safety concerns, according to a Wall Street Journal report.

The Google barges were to be technology showrooms for the company, but contractor Foss Maritime Co. halted the projects after the Coast Guard questioned the safety of the vessel, according to documents obtained under the Freedom of Information Act (FOIA).

The barges would contain 5,000 gallons of fuel on the main deck, not to mention all the combustible material on board, according to a 2013 email to the contractor from the Coast Guard.

Google’s secrecy surrounding the project caused it to request Coast Guard officials to sign nondisclosure agreements, and a Google official even wrote to the National Park Service saying it was worried about FOIA and the confidentiality of the project.

The park service, along with Google and Foss Maritime, all declined to comment, with the Coast Guard only saying in a statement that it had fulfilled its regulatory duties in inspecting the barges, and that they were not longer involved.

Barge construction began in 2011 and the tech behemoth originally considered using them as retail stores. By 2012, it was seeking approrval from the authorities. And by early 2013, the Coast Guard began detailing to Foss what it would have to do to ensure the safety of the ships if a fire were to break out.

Google had estimated that about 1,200 people per day would visit the barge in San Francisco, although only 150 would be on board at a time — something the Coast Guard didn’t buy into, noting that it appeared Google hadn’t made any attempts to limit passengers.

Google tried to woo authorities who were concerned with the company’s push for quick approrvals, but fire safety officials refused to sign off on the project. By September 2013, the project was halted.

In emails, a Coast Guard official expressed regret at signing nondisclosure agreements with Google, noting that it should have sought a legal review earlier.