Post-it note with handwritten message in red marker. The message reads: "All of New York City feels your pain."

Post-it note with handwritten message in blue marker. The message reads: "May you all rest in eternal peace. God Bless [heart]."

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 red marker. The message reads: "Hate is not welcome here." Tape on the upper edge.

Letter from a member of the Point Loma Community Presbyterian Church in San Diego, California. The letter reads: "Dear Members and Friends of the Tree of Life Synagogue, I am sorry for your loss in the recent shooting. Our prayers are with those affected by the attack and we hope that everyone injured is able to recover. Sincerely, Ben from the Point Loma Community Presbyterian Church in San Diego."

Letter from a member of the Point Loma Community Presbyterian Church in San Diego, California. The letter reads: "To our esteemed sisters and brothers I offer sorrow in your losses, comfort to enter into your memories and many blessings for your bright future as a synagogue to overcome. With all my love- Russell [last name redacted]."

Letter from a member of the Point Loma Community Presbyterian Church in San Diego, California. The letter reads: "Ellis [last name redacted] We pray that you will feel better. 2nd Grade. 7 years." The note is accompanied by illustrations of flower pots, stars, a heart, a smiley face, and a stick figure walking in grass with a sun in the background.

Hardwritten card in blue pen on white paper, offering condolences following the October 27 attack.

Folded card with colored pencil word art. Cover reads: "Have a good day". Interior reads: "Dear all, I'm so sorry to hear what happened there. We as a Beth Chai would like to send our heart to be there together. We believe world will be better. [Last name redacted for privacy] family."

White and purple envelope with handwritten inscription in blue ink addressed: "To: The family of Tree of Life." The location of the sender's home, Norfolk, Virginia, is inscribed in the lower left corner. The upper flap on the envelope's reverse is inscribed with the following note: "We are so broken hearted for your loss." Staining and creasing due to exposure to the elements at the Wilkins memorial.

Zine page with bubble letters and information about the emotional value of hugs. Zine page with cartoon imagery and information about the value of hugs. A young boy hugs a globe, beneath the inscription: "Embrace the world one hug at a time."

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 and divine love. The church's contact information is included on the back of the envelope.

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

Card with colored pencil illustration. Cover features an illustration of a leafy tree with pink asterisk-shaped stars, labeled: "The place where new life can grow." Inside reads: "Baruch dayan ha'emet" in English and Hebrew, and "I am sorry for your friends and families loss. I know what it feels like. So I am sending all the way from Texas this blessing." The back is signed: "Miriam." Spelling errors have been corrected in this transcription.

Handwritten card in pink and orange marker on pink paper. The card reads: "Sorry for this tragedy. We love! Adeline." A large, striped, inverted triangle appears below the word "Sorry." Small hearts and peace symbols appear throughout.

Letter from a member of the Point Loma Community Presbyterian Church in San Diego, California. The letter reads: "Tree of Life Synagogue- We in San Diego stand with you and all send all our love. Tom and Linda [last name redacted]."

Handwritten card from a student at Goddard Middle School in Littleton, Co. The front cover features the following quote attributed to the great ancient Roman orator, Cicero: "While there's life, there's hope. -Marcus Tullius Cicero." An illustration of a large Star of David appears below. The quote and illustration are outlined with a repeating pattern of blue and white lines. The inside reads: "Dear L'Simcha Congregation, My name is Olivia [last named redacted]. I live in Littleton, Colorado. I am Jewish.