Typed Hebrew letter from a student at Hebrew Academy, a private Jewish day school in Montreal, Quebec. Translated into English, the letter reads: "Dear Rabbi from the Tree of Life Congregation, My name is Hannah [last name redacted]. I am a student at Hebrew Academy of Montreal. I am truly sorry about what happened to your holy synagogue. I hope that this will not happen again. I give [?] all your family and loved ones of your synagogue."

Handout on grief, trauma, and critical incident stress debriefing, which was sent with the materials from Emergency Ministry Services, a faith-based training and disaster response NGO in San Juan Capistrano, Ca., affiliated with the Orange County Church on the Rock.

Card from a student at West Allegheny Middle School in Imperial, Pa. The front features a hand-colored illustration of the words: "Be Strong" and other floral and geometric motifs. The back contains a handwritten note, as well as the stock signature: "From your friends at West Allegheny Middle School."

Post-it note with handwritten message in black marker. The note is written in Hebrew. Translated into English, it reads: "Be strong, be strong, and may we be strengthened!"

Oral history of Tracy Baton, recorded as part of the Meanings of October 27th Oral History Project.

Post-it note with abstract illustration in blue and green marker.

Hallmark card from a member of St. Peter's Episcopal Church in Londonderry, New Hampshire. The envelope features an illustrated heart. The front cover reads: "Peace" and features a sandy landscape with a blue sky and orange flowers. The inside reads: "We are sending you so much love- and will stand with you in peace forever- with you in peace. Steve and Bailey."

Handwritten card from a student at Goddard Middle School in Littleton, Co. The front cover features a large Star of David and contains the following quote attributed to Albert Einstein: "Life is like riding a bicycle. To keep your balance, you must keep moving." The inside reads: "Dear Rabbi Jeffrey Myers, I am sorry for your loss, and violence. I am a student from all the way from Denver, Colorado. So from all of us from Colorado we give you good wishes. Sincerely, Will [last name redacted]."

Square card with white and yellow text against blue background. Card reads, "Mitzvah4Pittsburgh. Some spread darkness. We spread light. Choose a good deed. Choose a Mitzvah. Add light to the world," followed by four options and a place for respondents to list their name and email address. Some names and email addresses have been redacted for privacy.

Card on red paper from three students [last names redacted] at Magen David Yeshivah High School in Brooklyn, Ny. The upper flap inside is illustrated with a large heart, surrounded by smaller hearts, and two Stars of David. A sun appears on the left, labelled with the quote: "after the rain, the sun shall shine through." The card ends: "GET WELL SOON! [Star of David]."

Post-it note with handwritten message in blue marker. Tape in the upper left corner. The message reads: "This Temple's response to all this hate is beautiful. Hate is not welcome here or anywhere! My blessings to all."

White posterboard with handwritten messages of support from the Thornhill Rebels in Toronto.

Floral tag from floral arrangement sent by the Waltons. The tag reads: "Rest in Peace- with love from your old neighbors, The Waltons." The note is handwritten in black ink on a printed tag with blue hydrangeas on the left edge.

Post-it note with handwritten message in green ink. The message reads: "We cannot change the past, but we can inspire the future. Let what's happened here be a warning to us all that there is no room for hate anymore."