Police said four people were killed in a shooting at a medical center in Tulsa, Oklahoma, on Wednesday, the latest in a wave of deadly gun violence across the United States.

Authorities say a gunman opened fire on the St. Francis Health System campus Wednesday afternoon, shooting multiple people with at least two firearms. Tulsa Police Department Deputy Chief Eric Dalgleish said authorities responded to a call after dispatchers received the report and made contact with the gunman.

During a press conference, Dalgleish confirmed the death toll and stated that the shooter had also died, apparently from a self-inflicted gunshot wound. Officers found the shooter and several victims on the second floor of the St. Francis Health System’s Natalie Building, about eight miles southeast of downtown Tulsa, according to Dalgleish.

An outpatient surgery center and a breast health center are located in the Natalie Building. According to Dalgleish, the second floor also houses an orthopedic clinic.

During the shooting on Wednesday, the entire hospital campus was locked down.

In addition to the suspected gunman, at least four people were killed in the shooting, and several others were injured, according to police. The medical complex was described as a “catastrophic scene” by authorities, who have not released the identities of the victims or a possible motive.

According to The New York Times, Tulsa Police Capt. Richard Meulenberg stated, “It wasn’t random.” “This wasn’t some random person who decided he wanted to go find a hospital full of random people. He chose to come here on purpose, and his actions were deliberate.”

Dalgleish stated that the shooter had a rifle or “long gun” and a handgun, and that both weapons appeared to have been fired at the scene.

According to the Muskogee Police public information officer, an Oklahoma Highway Patrol bomb squad used dogs to clear a home in Muskogee after police were notified that the hospital shooter may have left a bomb inside.

“There were no devices discovered,” Lynn Hamlin said.

After that search, Tulsa police investigators arrived “and took over the scene,” she said. Muskogee is located approximately 50 miles southeast of Tulsa.

During a news conference Wednesday, police said that at 4:52 p.m., dispatchers received a call about an active shooter in the Natalie Medical Building on the St. Francis Health System campus.

Officers arrived at the scene four minutes later, according to police. After hearing gunshots on the second floor of the building, officers made contact with the victims and the shooting suspect at 5:01 p.m., according to authorities.

“I was very pleased with what we know so far about our officers’ response,” Dalgleish said.

After the shooting on Wednesday, residents waited to hear from their loved ones at the designated reunification area.

Kevin Foristal of Broken Arrow, Oklahoma, said his wife was receiving outpatient therapy at the main hospital building’s infusion center at the time of the shooting.

He was “elated” to hear she was safe, but added, “There are people out there who aren’t going to let that happen.”

Johnnie Munn arrived at the reunification site on Wednesday night to assist in the provision of food, water, and emotional support. As a senior disaster program manager for the Red Cross, the Tulsa native specializes in mass shooting response.

He has attended to victims at the site of the deadliest mass shooting in US history, which occurred in Las Vegas in 2017, killing 60 people. He was responding to a fatal attack in his hometown this time.

“It’s surreal and aggravating,” Munn said. “You’re like, ‘Why?’ … It’s no surprise that it’s happening more often.”

Dr. David Holden, President of the Oklahoma State Medical Association, said in a statement that the organization was heartbroken to learn of the deaths at the Tulsa hospital.

In recent weeks, there have been a number of high-profile shootings in the United States, including two massacres in Buffalo, New York, and Uvalde, Texas.

The attack on Wednesday was the second mass shooting in Oklahoma this week: a woman was killed and seven others were injured during an annual Memorial Day festival in Taft, a small town near Muskogee, according to the Oklahoma State Bureau of Investigation. The suspect in the shooting later turned himself in.