VIRGINIA BEACH, Va. — A longtime, disgruntled city employee opened fire at a municipal building in Virginia Beach on Friday, killing 11 people before police fatally shot him, authorities said.

Six other people were wounded in the shooting, including a police officer whose bulletproof vest saved his life, said Virginia Beach Police Chief James Cervera.

Five patients were being treated at Sentara Virginia Beach General Hospital and a sixth was being transferred to the Trauma Center at Sentara Norfolk General Hospital, Sentara Healthcare tweeted.

The shooter opened fire in Building 2 of the municipal center, which is adjacent to City Hall. The building houses the city’s public works, public utilities and planning departments, according to City Councilwoman Barbara Henley, who arrived at City Hall building about 4 p.m. Friday just after the shooting.

Megan Banton, an administrative assistant who works in the building where the shooting happened, said she heard gunshots, called 911 and barricaded a door.

“We tried to do everything we could to keep everybody safe,” she said. “We were all just terrified. It felt like it wasn’t real, like we were in a dream. You are just terrified because all you can hear is the gunshots.”

She said she texted her mom, telling her that there was an active shooter in the building and she and others were waiting for police. Banton works in an office of about 20 people that is part of the public works department.

“Thank God my baby is OK,” Banton’s mother, Dana Showers, said.

Cervera identified the shooter as a disgruntled employee of the Public Utilities Department. He did not release his name.

Christina Pullen, a spokeswoman for the FBI in Norfolk, said the bureau is assisting.