Rev. Van Jordan, of Port Arthur, Texas, leads a group prayer while setting up crosses to honor the shooting victims along the edge of a field next to Sutherland Springs First Baptist Church in Sutherland Springs, Texas on November 8, 2017. (Photo by Carolyn Van Houten/The Washington Post)

SAN ANTONIO — The first surgery Brian Eastridge ever performed on a deployment involved a soldier whose leg had just been blown off by a land mine. The soldier’s job was to clear land mines — in a war zone, no less — so the risk of traumatic injury, while significant, was hardly surprising.

In the 12 years and six deployments to Iraq and Afghanistan since then, Eastridge, a U.S. Army surgeon, has seen lots of blast wounds like that one, as well as lots of injuries caused by high-velocity bullets, which mimic an explosion, sending powerful shock waves into surrounding tissue as they travel through the body. That’s war.

But in San Antonio, where Eastridge now serves as the chief of trauma at University Hospital, the injuries tend to be more mundane. Car crashes and falls. Workplace accidents and gunshot wounds — of which there are many — but even those tend to come from handguns, which usually cause less damage.

Then on Sunday, Eastridge experienced his first mass shooting outside of a war zone. And soon came the victims with the catastrophic wounds typically reserved for war, coupled with the discombobulating fact that these were ordinary civilians and that all of this happened during a church service in the United States.

“When we take a patient to the operating room, we have a set approach,” Eastridge said in an interview Tuesday. “But really, after all the dust settles, there’s a big emotional burden. . . . It is gut-wrenching to look into the eyes of a dying child.”

Devin Kelley, a 26-year-old Texan, used an assault rifle with high-velocity rounds to open fire during a Sunday church service in nearby Sutherland Springs, killing 26 people and wounding just about everyone else in the sanctuary.

Four children and five adults who survived arrived at Eastridge’s hospital an hour later with devastating injuries to their chests, abdomens, arms and legs. Doctors rushed to perform multiple surgeries, and they readied themselves for the unpredictability of such wounds, knowing that the shock waves from the fast-moving bullets would kill swaths of surrounding tissue that wasn’t directly struck.

Within the first three hours, one of the children died on the operating table. Two other children and an adult remained in critical condition Wednesday, after undergoing several surgeries.

The hospital staff is “pretty banged up” by all this, Eastridge said. And he’s rattled, too.

Hospitals train for mass casualty events like these. “We live in a city that has an airport, so we consistently have to drill for plane crashes. We live in a city that has a fair amount of industry, so we always have a hazardous-materials plan,” Eastridge said. “But probably in the last four to five years, we’ve been very rigorous about training for the active shooter.”

Earlier this year, the hospital also started offering monthly classes to the public — part of the federal Stop the Bleed campaign that grew out of the response to mass shootings — that train ordinary people to stanch the potentially deadly flow of blood from major injuries, like those caused by gunshots.

Why have mass shootings grown more common over the past few decades? What would make them stop? Eastridge finds it all frustrating and upsetting, but he doesn’t have any answers.

“Everybody has got an opinion whether this is all about guns, or this is all about mental health, or just about intolerance. That tends to be my view — that this is just people being hateful and intolerant,” said Eastridge, who is a gun-owner and who voted for Donald Trump in the 2016 election.

Still, he can’t think of why people have grown more intolerant.

“I have thought about that very question. And I don’t know,” he said. “It does seem that over the last couple of decades, people are just less and less tolerant of one another.”