Scalise was in stable condition.
The gunman was shot by U.S. Capital Police, apprehended and taken to the hospital, officials said. Sen. Mike Lee told Fox News, however, the gunman was killed. The incident occurred at Simpson Field in Alexandria, about 10 miles from Washington D.C.
Rep. Roger Williams, R-Tex., was seen being taken from the field in a stretcher but it was unclear if he was struck by a bullet.
"Finally the shooter was shot behind home plate as he was circling around to the first base dugout where there were a number of us congressmen and other folks," Rep. Mo Brooks told FMTALK1065. "Our security detail was able to incapacitate him at that point. I don't know if he [shooter] was dead. He was wounded. I don't know how many times he was wounded."