A gunman opened fire at a FedEx warehouse in Indianapolis late Thursday, killing at least eight people and wounding multiple others, authorities said.The latest: President Biden, who was briefed on the shooting by Homeland Security officials on Friday, ordered flags at the White House, public buildings and grounds, military posts and embassies to be lowered at half-staff.Stay on top of the latest market trends and economic insights with Axios Markets. Subscribe for free"Gun violence is an epidemic in America. But we should not accept it. We must act," Biden said in a statement, noting that the Indianapolis shooting occurred the night before 14th anniversary of the shooting at Virginia Tech that killed 32 people. "Too many Americans are dying every single day from gun violence. It stains our character and pierces the very soul of our nation."The Indianapolis Metropolitan Police Department held a briefing on Friday morning, but could not offer any major new details because investigators are still attempting to identify the shooter and any victims.Paul Keenan, the FBI agent in charge of the Indianapolis field office assisting with the police department's investigation, said during the briefing that it would be "too premature" to speculate on the shooter's motive.What happened: "The alleged shooter has taken his own life here at the scene," Indianapolis Metropolitan Police Department spokesperson Genae Cook said during a news conference early Friday. At least four people were hospitalized, one with critical injuries, and two others were treated at the scene and released, Cook said.The gunman is believed to have been acting alone, and there's no longer an "active threat to the community," she added.What they're saying: FedEx said in a statement on Friday that it was "shocked and saddened" by the shooting and expressed sympathies to "those affected by this senseless act of violence.""Our priority right now is in responding to the situation on the ground and helping our team members and law enforcement," FedEx CEO Frederick Smith said Friday in a second statement. "We have a team onsite in Indianapolis to provide support, and we are making counselors available."The big picture: This is the latest in a string of deadly mass shootings to hit the U.S. since March, reinvigorating the political debate in Washington over gun control.Editor's note: This article has been updated with new details.Like this article? Get more from Axios and subscribe to Axios Markets for free.