It was a day of sorrow on Capitol Hill as lawmakers grappled with the shooting deaths of nine African American churchgoers overnight in Charleston, S.C.

Members took to social media to express their sadness, confusion and resolve in the face of tragedy. The most moving posts came from South Carolina lawmakers, including Rep. James Clyburn (R-S.C.), the House’s highest-ranking African American whose 6th congressional district includes parts of Charleston.

Sen. Tim Scott (R-S.C.), who was born in North Charleston, had these reflections:

Congressional leaders also offered their condolences:

A tweet from CBS News White House Correspondent Mark Knoller was widely circulated ahead of remarks by President Barack Obama: