Calls to close the country’s national parks are increasing amid reports that three people have died since the start of the government shutdown, reports the Washington Post. Among the dead is a 14-year-old girl who fell 700 feet down a canyon in Arizona. A man also died at Yosemite National Park on Christmas, and two days later a woman was killed by a falling tree at Great Smoky Mountains National Park. Although deaths and national parks are hardly uncommon—an average of six die each week in the park system, according to a spokesman—the series of deaths does shine a spotlight on the decision by the Trump administration to keep them open even as staffing has been kept to a bare minimum, if there is any at all.

The move to keep the parks open differentiates this shutdown from most in the past. In 1995 and 2013, for example, the parks were shut. And while the parks did stay open last year, that shutdown only lasted three days. Now the shutdown has entered its third week and many are saying it’s time to close the parks. Trash is piling up, sure, but many experts also say the safety of visitors is compromised with fewer staff members present. “I think we all know that not having bathrooms is a nuisance. What I think people forget is, not having adequate sewage treatment can be dangerous,” Diane Regas, president and chief executive of the Trust for Public Land, said. “When you bring people together, running these parks is like running a small city.”

Ryan Zinke, who recently stepped down as the secretary of the Interior Department, says everyone needs to pitch in to keep the parks clean. But it’s clear many visitors are also not being the most thoughtful when it comes to visiting parks during the shutdown. “At Joshua Tree and Yosemite, impacts from human waste is a concern, which includes people relieving themselves in public places, such as behind buildings [and] on roadsides,” said Andrew Muñoz, a park service spokesperson.

Volunteers are teaming up with nonprofits and state governments across the country to try to keep parks safe and clean, but some are warning that these makeshift operations were not set up to last more than a few days. Trump said on Friday the shutdown could last “months or even years.” Even some who have long advocated to keep parks open say enough is enough. “It’s really an awful situation to be in, but our primary job is to protect park resources and the safety of the public,” said Phil Francis, the chairman of the Coalition to Protect America’s National Parks. “I hate it. I always advocated for keeping the parks open and finding a solution, but when you’re unable to protect the park resources and protect the visitors, it changes how you have to look at it.”