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

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

During a news conference, Dalgleish confirmed the number of dead and said the shooter also was dead, apparently from a self-inflicted gunshot wound.

Wednesday’s attack comes after two high-profile shooting massacres in Buffalo, New York, where 10 Black people were killed, and Uvalde, Texas, where 19 children and two teachers were killed in May.

Here’s what we know about the deadly shooting in Tulsa:

‘SENSELESS ACT OF VIOLENCE AND HATRED’:At least 5 dead, including suspect, in Tulsa medical center shooting

Where did the attack take place?

Dalgleish said officers discovered the shooter and several victims on the second floor of the St. Francis Health System’s Natalie Building, about eight miles southeast of downtown Tusla.

The Natalie Building houses an outpatient surgery center and a breast health center. Dalgleish said an orthopedic clinic also is located on the second floor.

The entire hospital locked down its campus Wednesday during the shooting. 

Police: Tulsa shooting ‘wasn’t random’

At least four people were killed in the shooting besides the suspected gunman, and several others were injured, police said. Authorities, who have not released the identities of the victims or a possible motive, described the medical complex as a ‘catastrophic scene.”

“It wasn’t random,” said Tulsa Police Capt. Richard Meulenberg, according to The New York Times. “This wasn’t an individual who just decided he wanted to go find a hospital full of random people. He deliberately made a choice to come here and his actions were deliberate.”