Handwritten card from a student at Goddard Middle School in Littleton, Co. The front and back cover reads: "One of the happiest moments ever is when you find the courage to let go of what you can change." The inside reads: "Dear Tree of Life Congregation, I am so very, very sorry for your loss (losses). I know what it's like to lose someone. I am Camden. I am a student at Goddard Middle School. I am 13. I think that what happened with the shooting was not ok. Just because people have beliefs that are different it doesn't give people the right to do something that.

Floral tag with blue hibiscus flowers. The tag contains a handwritten note reading: "Our deepest sympathy. Namachar family."

Card from a congregant at the Holy Angels Parish. The front cover contains a stock illustration of seven children holding hands around a table with a large goblet and loaf of braided bread, and seven doves. The illustration is labeled: "We are people of God's peace." The inside reads: "Just because life is hard now...does not mean it will be forever challenging. Love in stronger than HATE. You just have to strong. We are praying. -Tree of Life members and all Jewish people. - From: Reena Weber and Holy Angels CCD, 8th grade." Illustrated with two small hearts.

Note from a member of The Church at Severn Run in Severn, Maryland. The note is enclosed in an envelope with church letterhead, reading: "The Church at Severn Run: Love Well, Live Jesus, Believe Big!" The note inside contains messages of support, love, and prayer. The church's contact information is included on the back of the envelope.

Post-it note with handwritten message and illustration in black marker. The note is signed: "[heart] Dorothy" and features two abstract circle and oval shaped illustrations.

Post-it note with handwritten message in blue marker. The message reads: "We love you. Love, Sophie."

Letter from a member of the Point Loma Community Presbyterian Church in San Diego, California. The letter reads: "Dear Tree of Life Synagogue, Brothers and sisters, we love you and are praying for all of you in this difficult time. Love, The Pasha Family."

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.

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.

Post-it note with handwritten message in black ink. The message reads: "God's love for the Jews, his people is stronger than the wicked mess of the evil. May the Jews be blessed forever. H. [last name redacted]." Staining and color bleeding due to exposure to the elements at the Wilkins memorial.

Handwritten card written in pencil on paper. The card reads: "Dear Family, Hello my name is Elisha D. I am from Netivot, we stand together with you because a loss for you is a loss for us. May you only see simchas."

Handwritten card in pencil on paper. The front of the card reads: "L'chaim" (to life) in Hebrew. It is illustrated with a Menorah. Color bleeding due to exposure to the elements at the Wilkins memorial.

Printed signs in blue and green ink on paper. The signs urge the reader to "Show solidarity" and "stand up for our common values, today tomorrow and always." An illustration of three stylized people raising their hands appears in the upper center, surrounded by the words: "Kindness, Respect, Courage."

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

Card from a student at West Allegheny Middle School in Imperial, Pa. The front features a hand-colored illustration of the words: "Don't Stop Believing." The back contains a handwritten note, as well as the stock signature: "From your friends at West Allegheny Middle School."

Card from the Friendship Circle of Illinois. The front cover reads: "To: The Jewish Community of Pittsburgh. From: Yisroel [last name redacted], Chicago IL." The inside reads: "I feel so sad for you. My hachlata (resolution) is to give 3 cents instead of 1 or 2 cents. You should have everything you need. And Hashem (God) should give you all that you need." Spelling errors have been corrected for clarity.

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

Card made by a student from the George Washington University Hillel. The front cover reads: "Hugs" with asterisks on either side. The inside (from right to left) reads: "Sending you messages of hope, love, and comfort from Washington D.C. Love, Alex. May God be with you and your families."