() — President Donald Trump may be fulfilling his promise to reopen Alcatraz, the notorious and long-shuttered prison off the coast of San Francisco, to house America’s “most ruthless and violent” criminals.

Attorney General Pam Bondi and Interior Secretary Doug Burgum visited the island on Thursday and are expected to make an announcement, a source familiar with the trip confirmed to .

Alcatraz, also known as “The Rock,” was a federal prison that operated between 1934 and 1963, when it was closed because of high operating costs.

Today, the former prison is a popular museum and tourist destination, operated by the National Park Service and protected from development. However, Congress could pass new legislation to change that.

‘Rebuild, and open Alcatraz’: Trump

In May, Trump directed the Bureau of Prisons and other federal law enforcement agencies to expand and reopen the prison, writing on social media, “REBUILD, AND REOPEN ALCATRAZ!”

He said the reopening would serve as a “symbol of Law, Order, and JUSTICE.”

Trump couched his plan it wasn’t immediately known how viable it would be as a way to get tough on crime. He targeted what he called repeat offenders and the “dregs of society.”

“When we were a more serious Nation, in times past, we did not hesitate to lock up the most dangerous criminals, and keep them far away from anyone they could harm. That’s the way it’s supposed to be,” Trump wrote.

Nancy Pelosi condemns Trump’s proposal to reopen Alcatraz

Speaker Emerita Nancy Pelosi, D-Calif., criticized Thursday’s visit, calling the push to reopen Alcatraz the “stupidest initiative yet” for the Trump administration.

In a statement, she wrote, “It should concern us all that clearly the only intellectual resources the Administration has drawn upon for this foolish notion are decades-old fictional Hollywood movies.”

Pelosi, whose congressional district includes Alcatraz Island, added that if Trump’s plan ever reaches Congress, Democrats will fight against it.

What is Alcatraz, and why was it closed?

Alcatraz, derived from the Spanish “Alcatraces,” was originally used as a citadel in the 1850s, and the government’s first prisoners arrived onshore by the end of the decade.

In 1909, the U.S. Army destroyed the citadel, and its military prisoners began construction of a lockup in the fortress’ footprint, according to the Federal Bureau of Prisons. The Department of Justice took control in 1933, and it opened in 1934.

Alcatraz is surrounded by frigid waters and not-so-deadly sharks. It housed notorious Chicago mob boss Al Capone and Robert Stroud, a convicted murderer who studied birds on the island from behind bars, who was known as the “Birdman of Alcatraz.”

Notably, it was the site of many escape attempts 14, to be exact, involving 36 men in total though no one ever successfully made it to shore, according to official records.

The decision to close Alcatraz was one of logistics, according to the Bureau of Prisons.

It cost the U.S. government roughly $3 to $5 million just to keep the prison open, excluding daily operating costs, making it nearly three times more expensive than other federal prisons.

The island’s physical location, while ideal for keeping prisoners trapped, required fuel, food and nearly 1 million gallons of fresh water barged in each week, according to the National Park Service.

‘s Anna Kutz and Michael Ramsey contributed to this report.