in pittsburgh today, the gunman who killed 11 people at a synagogue was formally sentenced to death. but for the tree of life congregation and the community around them, the scars have not yet healed. we get more from david johnson of our nbc affiliate in pittsburgh, wpxi. >> reporter: senseless violence shattered squirrel hill, the heart of pittsburgh's jewish community when a mass shooter took the lives of 11, wounding 7 at the tree of life synagogue, committing the most deadly act of anti-semitism in u.s. history. >> i was there that morning to read torah. >> reporter: stephen weiss survived that day. >> one of the important foundational parts of judaism is we are a community. we can all stay home and pray in isolation at home. that's why i think we go to synagogue, why we try to be together as community. there is more strength in numbers, and we gain strength from each other when we're together. >> reporter: the jewish community is increasingly at risk with anti-semitic attacks up 36% last year, the highest in