NEW YORK (NYT NEWS SERVICE).- The location of where they work is a secret they keep, even from old friends.

The artisans who operate out of the Solomon R. Guggenheim Museum’s storage facility on the West Side of Manhattan have long understood that it is part of their job to keep quiet about their place of employment, an off-site warehouse filled with much of the world’s finest art.

So now, even as they shelter at home and worry about possible furloughs or layoffs by a museum struggling without admission revenue, the workers who help maintain the collection and prepare it for display say they understand the commitment they have made.

“They feel a moral responsibility to protect this work,” said Andres Puerta of Local 30 of the International Union of Operating Engineers, which represents those workers. “They know the heavy weight of that responsibility.”

Their concerns are mirrored across the quiet streets of a shuttered world, as museums work to figure out how to contend with the possibility of enhanced security risks. Alarm systems and uniformed guards are still in place, of course, and the sale of museum-famous stolen art has never been easy.

But the pandemic has meant the closure of institutions and reductions in staffing. Cavernous floors are now largely empty throughout the day, not just at night. Police departments in many places are stretched thin by illness. Social distancing has meant that the many people who might once have witnessed a burglary are now tucked in at home.

“The risk is serious,” said Steve Keller, a museum security consultant who has worked with the National Gallery of Art, the Smithsonian Institution and others. “Thieves might think the museums are in a weakened condition, and that increases the threat.”

Last week burglars broke into a small museum in the Netherlands that had closed because of the coronavirus and absconded with an early van Gogh painting, “The Parsonage Garden at Nuenen in Spring.” Police responding to the museum’s alarm found a shattered glass door and a bare spot on the wall where the painting had been.

Two weeks earlier, a gallery at the University of Oxford, also closed by the virus, lost three 16th- and 17th-century paintings, including “A Soldier on Horseback” by Flemish artist Anthony van Dyck, to thieves.

Museums, understandably, do not discuss their security measures or concerns, except to say that standard safeguards are in place.

“The museum’s buildings are as secure under current circumstances as they ever are,” said a spokeswoman for the Houston Museum of Fine Arts, which has guards on duty 24 hours a day.

A spokesman for the Metropolitan Museum of Art said simply: “Sorry but we just don’t talk about security procedures.”

Keller and Stevan Layne, founding director of the International Foundation for Cultural Property Protection and a former director of security at the Denver Art Museum, said that museums are not necessarily more vulnerable now. Still, they recommended that institutions make sure alarm systems are functioning properly and that they more closely restrict entry to museum buildings.

“Just because a curator left a pair of glasses on a desk, that is not an emergency,” Keller said.

In an email message, a spokeswoman for the Guggenheim cited some of the same precautions.

“The Guggenheim Museum continues to maintain 24-hour security operations with increased monitoring of all facilities and offices,” wrote the spokeswoman, Sarah Eaton. “During this time of closure, no unauthorized or unexpected guests or personnel are being permitted entry into the museum or off-site locations until further notice.”

The New York Police Department, which helps to protect the Guggenheim and other museums, has been hit hard by illness. As of Monday, for instance, nearly 7,000 of its uniformed members were on sick report, which accounts for just over 19% of the department’s uniformed workforce. In addition, officers have been making thousands of trips a day to ensure that bars and restaurants are closed and that people follow proper social distancing practices at supermarkets and in public places.

Crime overall was down in New York City during the second half of March compared with the same period last year. But burglaries were up by nearly 17%.

A police spokeswoman, Sgt. Jessica McRorie, said in an email message that “the NYPD has adapted swiftly and with success” to the challenges brought on by the virus.

Asked whether high-profile targets like museums were being given special attention, McRorie wrote: “The commanding officer of a precinct decides if additional patrols will be conducted at a location and that decision is based on conditions specific to the precinct and available resources.”

For the duration of the pandemic, Keller said, museums should assume that they would be in permanent “night mode,” relying on security measures that are generally in place when institutions close for the evening.

He said that some systems, like alarms, cameras and motion detectors, which if properly configured can show whether a person might be moving from gallery to gallery, could still be an effective counter to burglars, especially if security guards and other essential personnel like building engineers are provided with radios so any potential incursion can immediately be investigated.

And while museum galleries containing certain artworks, like those on paper, could suffer from prolonged exposure to light, Keller said he had suggested that clients permanently turn on lights in other galleries so that any activity there could be seen, day or night, by guards watching monitors.

Insurance levels would probably remain the same, he said, unless a museum was displaying works that were on loan from another institution. In that case, Keller said, the borrowing museum might adjust insurance to make sure the items on loan were covered.

All museums operate differently, but they typically carry insurance that would provide coverage in the event of theft, fires and floods. Insurance for a permanent collection may be written on a blanket basis instead of tied to a list of specific works. And some experts advise carrying insurance that will cover an amount equal to the part of a collection that may be lost or destroyed at any one time and making sure that losses are payable based on market value at the time of a loss.

Beyond that, Keller said, he had advised museums to spread its most experienced security people out among shifts and make sure that the same teams of guards always worked together to lessen the chance that a single guard falling ill could infect an entire security force.

At least one museum, he said, had set up cots and provided food so that a group of guards could essentially live inside the institution, isolated from anyone who may have contracted the coronavirus and providing a round-the-clock presence.

But Keller said that the longer the pandemic went on, the more that security guards would have to compensate for the absence of regular museum workers whose eyes and ears can help protect institutions from more mundane problems — like leaky pipes that can damage artworks or a desk lamp left on too close to a stack of paper that could start a fire.

“The guards are going to have to be a little more attentive to environmental conditions around the building, the smell of smoke or the sound of water dripping,” he said. “Those are threats to the collection just as much as a thief is.”

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