President Obama will visit Boston on Thursday, three days after a pair of deadly bombings at the Boston Marathon.
Massachusetts Gov. Deval Patrick says Obama will be attending an interfaith service.
Three people were killed at the marathon's finish line, including an 8-year-old boy. More than 170 were wounded.
Hours after the explosions, Obama vowed that those responsible would be brought to justice. In remarks on Tuesday, he called the bombings an act of terrorism but said investigators still don't know who carried them out.
He also said the American people refuse to be terrorized.
Obama has traveled four times to cities reeling from mass violence, but all of the previous trips followed shooting incidents. The most recent was in December after the schoolhouse shooting in Newtown, Conn.