President Joe Biden and other Democrats offered condolences and condemnation after a lone gunman killed at least four people and wounded at least nine others Monday at a bank in downtown Louisville, Kentucky. 

Biden tweeted about the "senseless act of gun violence" just before 1 p.m. ET, offering prayers for the victims and their families, while also taking a shot at Republicans for refusing to support gun safety legislation.

"Too many Americans are paying for the price of inaction with their lives," Biden wrote on Twitter. "When will Republicans in Congress act to protect our communities?"

In a further statement, Biden thanked officers and first responders while highlighting the grief and trauma each survivor will carry. He further expanded on his calls for action, pushing for safe storage laws, stricter background checks and eliminating immunity afforded to gun manufacturers.

"A strong majority of Americans want lawmakers to act on commonsense gun safety reforms. Instead, from Florida to North Carolina to the U.S. House of Representatives, we’ve watched Republican officials double down on dangerous bills that make our schools, places of worship, and communities less safe," Biden said. "It’s unconscionable, it’s reckless, and too many Americans are paying with their lives."

The shooting, the 15th mass killing in the country this year, comes just two weeks after a former student killed three children and three adults at a Christian elementary school in Nashville, Tennessee, about 160 miles to the south.

Police in Louisville arrived as gunshots were still being fired inside Old National Bank and exchanged fire with the shooter, Louisville Metro Police Department Deputy Chief Paul Humphrey said at a news conference. It wasn't clear whether the shooter killed himself or was shot by officers, according to Humphrey.

An emotional Kentucky Gov. Andy Beshear, D-Ky., said he lost friends in the shooting in Monday's shooting at the East Main St. bank building, which is not far from the Louisville Slugger Field and Waterfront Park.

“This is awful,” he said. “I have a very close friend who didn’t make it today. And I have another close friend who didn’t, either. And one who’s at the hospital that I hope is going to make it through.”

Freshman Congressman Morgan McGarvey, D-Ky., who represents most of the Louisville metro area, called it a dark day for his community.

"Our community is one of far too many impacted by gun violence," McGarvey said in a statement. "Thoughts and prayers for those we lost, those who are injured, and their loved ones and families are appreciated, but today serves as a stark reminder that we need to address gun violence at the national level so no other family loses a son, a daughter, and a loved one."

Kentucky's Democratic state lawmakers, though they find themselves in slim minorities in the legislature, also sounded off on the need for change.

State Senate Minority Leader Gerald Neal, D-Louisville, offered his condolences for the victims, the families impacted and the first responders who were on the scene. Neal represents the area where the shooting took place.

"As we mourn and reflect on the devastating impact of today's events, we must come together as a community and society to find effective solutions in preventing the continuing scourge of gun violence," Neal said. "We must do all that we can to take effective steps to ensure a safer community.

Rep. Keturah Herron, D-Louisville, lamented that Monday was just Louisville's turn in the cycle of constant tragedy. "This is happening around the country in a city daily," Herron wrote on Twitter.

"As we hold our community tighter there must [be] outrage and anger. We live in a war zone and we shouldn’t have to."