San Francisco, United States — Donald Trump's plan to reopen Alcatraz was mocked online Monday by people who suggested the US president got the idea from watching TV.

The order to resurrect the once-notorious island prison in San Francisco Bay came out of the blue over the weekend with a post on Trump's social media platform.

"Today, I am directing the Bureau of Prisons, together with the Department of Justice, FBI, and Homeland Security, to reopen a substantially enlarged and rebuilt ALCATRAZ, to house America's most ruthless and violent Offenders," he said.

The island fortress entered American cultural lore after a 1962 escape by three inmates, which became an inspiration for the film "Escape from Alcatraz" starring Clint Eastwood.

Social media users were quick to spot that the film had been shown on television in south Florida on Saturday night including in West Palm Beach, where Trump spent the evening at his Mar-a-Lago resort.

"Is it possible Trump watched the movie and got caught up in it? Which led to the so-called brilliant idea of rebuilding Alcatraz?" wrote @HansonRitta on X.

"Are we getting American policy from TV shows?"

"This is really funny," wrote @MatthewSpira.

"We're going to spend a half billion dollars fixing up Alcatraz to never serve as a supermax in the San Francisco Bay all because an old man was bored and flipping through channels on a Saturday night."

No sharks

Asked Monday how he had come up with the idea, Trump appeared to acknowledge the cinematic influence.

"I guess I was supposed to be a movie maker," he told reporters in the Oval Office.

"It represents something very strong, very powerful, in terms of law and order," he said.

"Nobody ever escaped. One person almost got there, but they... found his clothing rather badly ripped up, and it was a lot of shark bites." he said.

The Bureau of Prisons (BOP) notes on its website that 36 people tried to escape from Alcatraz and while most were caught or died in their attempts, the fate of five is unknown and they are listed as "missing and presumed drowned."

But they definitely didn't get eaten by sharks -- a popular myth that has surrounded Alcatraz.

"There are no 'man-eating' sharks in San Francisco Bay, only small bottom-feeding sharks," the BOP says.

However the president got the idea, his new prisons director William Marshall told US media he was working on the plan.

"The Bureau of Prisons will vigorously pursue all avenues to support and implement the President’s agenda," he said.

"I have ordered an immediate assessment to determine our needs and the next steps. 

"We will be actively working with our law enforcement and other federal partners to reinstate this very important mission."

High costs

Alcatraz -- originally a military garrison -- closed in 1963 due to high operating costs after being used as a prison for just 29 years.

Because of the physical isolation of the island, operation costs were three times those of other institutions in the US, with food, supplies, fuel and even drinking water having to be brought to the island every week.

Maintenance and restoration work required at the time of its closure would have cost up to $5 million, and officials decided it was cheaper to build new prisons elsewhere instead.

The island was occupied for 19 months from November 1969 by Native American protestors, who said they were reclaiming abandoned federal land.

In 1973 it became a tourist site, and now attracts more than one million visitors each year.

Visitors can take a tour of the dilapidated cell blocks, where broken toilets remain in the spartan cells.

On an audio tour narrated by former inmates and prison guards, they are taken around the refectory, where guides explain how discipline was maintained -- and how it occasionally broke down.

The tour showcases the brutal, pitch-dark isolation cells in which prisoners were kept if they ran afoul of the feared warden.

Exhibitions detail the size of the prison population in the United States, and highlight how the system contains a disproportionate number of Black people and those from disadvantaged backgrounds.

A gift shop sells everything from t-shirts and posters to fridge magnets with institutional rules.

(Source: Bastien INZAURRALDE, AFP)