Dr. Jason Smith, University of Louisville Hospital's chief medical officer, said doctors who treated victims dealt with a "spectrum of injuries" consistent with an explosion, including blast injuries, thermal injuries and injuries from falling debris.

“I went to the scene yesterday afternoon and saw all of our amazing first responders and partner agencies working hard, working together, risking their lives to ensure that the scene was safe," said Louisville Mayor Craig Greenberg. "That we rescued as many individuals as possible, so that everyone who was impacted was safe and would be protected.”

Kentucky’s governor says investigators will find out what caused a deadly explosion that ripped apart a Louisville factory