A total of five were transported to the hospital.
Shortly after the shooting, Bernie Sanders, the former candidate for the Democratic presidential nomination, said on the Senate floor that the shooter apparently was a volunteer for his campaign a year ago.
"The Vice President and I are aware of the shooting incident in Virginia and are monitoring developments closely", Trump said.
"I heard a gunshot and I yelled to Trent, 'That was a gun!' And Trent looks over, he says, 'It's a shooter, '" Palmer said.
"I was looking right at him", Bishop told Detroit radio station WWJ. "He was a sitting duck".
Mr Scalise dragged himself off the infield leaving a trail of blood as colleagues rushed to his assistance.
Steve Scalise is the third-highest ranked member of the Republican leadership in the House and has the hard job of trying to keep order in the fractious party ranks and rounding up votes for bills. He was first elected to the House in 2008 after serving in the state legislature.
Duncan said he responded that it was Republicans.
Scalise represents the First Congressional District of Louisiana, which includes a small portion of New Orleans, and most of its western suburbs. Scalise is reported to be in stable condition.
"Prior to entering surgery, (Scalise) was in good spirits and spoke to his wife by phone", it added.
A congressman was among the victims at a shooting early Wednesday at a congressional baseball game. "We can all agree we are blessed to be Americans", Trump said. And we're praying for those injured in this heinous attack.