"I'm praying for all of the victims and their families and loved ones," said Rep. Steve Scalise (R-LA), who was seriously wounded in a gun attack last year on a group of Republican lawmakers, gathered for an early morning baseball practice outside of Washington, D.C.
"This is a senseless tragedy," said Sen. David Perdue (R-GA).
News of the shooting spread as the U.S. House was wrapping up work for the week, as Democrats swiftly demanded action in the Congress on measures dealing with gun violence.
"Children's lives are being cut short by senseless gun violence," said Rep. Juan Vargas (D-CA). "It is past time for Congress to act to prevent more innocent deaths."
"We have to stop this," said Rep. Seth Moulton (D-MA), as Democrats said Capitol Hill and the White House must act.
"We are not powerless," said Rep. Gerry Connolly (D-VA). "We are supposed to be leaders and take action."
"Congress and Trump must finally have the courage to stand up to the NRA and do what the American people want," said Sen. Bernie Sanders (I-VT). "Enough is enough!"