One person was killed and another was injured Tuesday by a shooter at a Delaware Hospital who remains at large, police said.

The attack was reported at 3:30 p.m. at ChristianaCare Wilmington Hospital in Delaware, Wilmington Police Chief Wilfredo Campos said at a news conference.

Arriving officers found both victims but no shooter, he said.

The chief offered no details about the victims, including their identities or the survivor’s condition, “out of respect for the families.”

A suspect description and possible motive were not available.

“We are actively working to identify and locate him,” Campus said, adding that officers will work “tirelessly” to bring the person to justice.

Mayor John Carney said hospital workers were “barricaded in rooms across the hospital as law enforcement cleared each of the floors.”

“This has been a terrible day for our city,” he said at the news conference.

Gov. Matt Meyer said his wife, Dr. Lauren Meyer, was reporting for work at the downtown hospital when the attack happened.

He called the hospital employees “heroes involved in life-saving efforts.”

U.S. Sen. Lisa Blunt, D-Delaware, said she had been briefed on the situation.

“As we wait for further information, I’m praying for our community and grateful for the swift and ongoing law enforcement response,” she said in a statement.

Wilmington is the state’s largest city, with a population of more than 73,000, and is sometimes referred to as the “corporate capital of America” because so many large corporations locate their legal addresses there.