One person was killed and four others injured in a mass shooting at a high-rise Midtown Atlanta hospital that put Georgia’s capital city on edge and immediately sparked calls for more action on gun safety.

The shooting happened early Wednesday afternoon in a waiting room at the Northside Hospital Midtown medical center on West Peachtree Street, causing the Atlanta Police Department to urge people to shelter in place for more than two hours.

The gunman was still at large as of late Wednesday afternoon.

Atlanta Police Chief Darin Schierbaum said all of the victims were women. The victim who died was 39 years old, and those who were injured were between the ages of 25 and 71. The shooter’s motive was not immediately clear.

“The clarity that I think that we would want to know as a city and as a society, we just don’t have at this particular moment, but we’ll provide it as soon as we can,” Schierbaum said.

Four patients were being treated at Grady Hospital in downtown Atlanta. Three of them were in critical condition as of mid-afternoon Wednesday, with the fourth in stable condition, according to a hospital spokesperson.

Georgia U.S. Sen. Raphael Warnock, who said his two young children were on lockdown at school, called for more congressional action on guns in a speech on the Senate floor a few hours after the shooting.

“This happened in a medical facility, where people are trying to find healing,” Warnock said. “I want to underscore that because there have been so many mass shootings – in fact, about one every day in this country this year – that, tragically, we act as if this is routine. We behave as if this is normal.

“It is not normal. It is not right for us to live in a nation where nobody is safe, no matter where they are,” he said, rattling off the long list of places where mass shootings have happened. “And still we have done so very little in this building.”

Congress passed modest gun safety legislation last year in the wake of a mass shooting at an elementary school in Texas that killed 19 children and two adults. It was the first major gun safety legislation passed in three decades.

“It was a significant piece of legislation, but obviously, it’s not enough,” Warnock said, decrying the resistance to universal background checks.

Under the Gold Dome, lawmakers have eased gun laws in recent years. Last year, Gov. Brian Kemp signed into a law a measure that ended the requirement for a permit to carry a firearm in public.

Schierbaum said police are searching for a suspect, 24-year-old Deion Patterson.

Police believe Patterson carjacked a vehicle near the hospital and fled before law enforcement arrived, Schierbaum said. By the afternoon, the search for Patterson had expanded into southern Cobb County.

“We have a multijurisdictional effort underway to bring this individual to justice and ensure that we remove him from the street. Everyone should consider him still armed and presenting a danger to whatever community he may find himself in at this time.”

Atlanta Mayor Andre Dickens said his office has been contacted by the White House for support.