Ahead of the white nationalist rally in Charlottesville, Virginia, the University of Virginia Medical Center cancelled all elective surgeries scheduled for Saturday, according to The Daily Progress, a daily newspaper for the Charlottesville area.

UVA Medical Center spokesman Josh Barney told the Daily Progress on Friday that elective surgeries scheduled for Saturday had to be rescheduled, in part because they had to prepare for the possibility of incidents that could require more operating room space.

The violent demonstrations have affected all facets of life in Charlottesville, with many businesses closing down for the day. But with UVA having to reschedule elective surgeries, doctors from across the medical community are concerned patients would be the ones to suffer the most. In a now-viral tweet, Dr. Eugene Gu, a general surgery resident at Vanderbilt University, wryly observed that elective surgeries “including for people with cancer” were cancelled at the UVA Medical center.

The “Unite the Right” rally was organized by white supremacists to protest the city’s decision to remove the Confederate statue of Robert E. Lee. Although city officials called on organizers to move the rally to a bigger venue because of safety concerns, a federal judge approved a preliminary injunction to allow the rally to continue on Saturday at the site of the statue in Emanicipation Park. After the ruling Friday night, white nationalists violently took to the University of Virginia campus with lit tiki torches. Saturday’s rally, while scheduled for noon, was over before it began as large scuffles turned violent with white nationalists using mace and pepper spray on counter-protesters. Virginia Gov. Terry McAuliffe (D) declared a state of emergency while Virginia State Police began making arrests after declaring unlawful assembly to clear the park.

To be clear, Gu is not a doctor at the University of Virginia and has not been on the ground in Charlottesville. But he is an experienced medical expert who understands the impact to patients when doctors cancel elective surgeries. In a phone interview on Saturday with ThinkProgress, Gu noted that patients have to be the ones to carry the burden of finding another time to quickly reschedule their surgeries.

Hospitals across the country generally clear their operating rooms to stand by for a potential mass casualty situation, a scenario that doesn’t sound that dramatic given what has transpired so far with gun-toting white nationalists fighting with people, and initial reports of possible casualties caused by vehicles driving into crowds.

“They have limited resources, even at a big hospital,” Gu said. “When you have elective cases that are occupying the operating rooms, then you can’t take in someone who, let’s say ‘someone got shot in the chest and he needs to be in the operating room now or he’s going to die.’ You need to have all the resources available to help in case of anticipatory trauma. Every major trauma center kind of has that in place.”

Gu said that there are certain elective cases like removing a cyst or a suspicious mole that can be put off for a week, or even a month. But what concerns Gu are the “elective” cancer cases that can’t wait as long.

“The cases that matter the most, I think in my opinion, are the cancer cases,” Gu said. “There are people with colon cancer, or breast cancer, or an unknown cancerous tumor. If you don’t remove it in a timely fashion, those tumors have a chance of spreading every day you don’t remove them. We want to get them done in a timely matter.”

“It’s called ‘elective’ because you won’t die if you don’t remove the tumor that day. You can wait a day, you can’t wait two days, you can wait a week,” Gu observed. “But sometimes our cases can be backed up. There’s limited OR [operation room] time. When you cancel someone’s cancer case, they may not get their case for another month. Or maybe that’s the only day the [patients] can make it, like maybe they’re from out of town.”

“Having [their surgeries] cancelled can be burdensome can be dangerous for cancer patients,” Gu said. “I was thinking of all the cancer patients that didn’t get their surgery as planned.”

“It’s a tragedy that we’ve come to this place in this country,” Gu added, referencing how white nationalists could descend on a university campus to promote such hate. “This is the most chilling thing I’ve seen in a long time.”