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."

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 affirms God's support and contains prayers for the families and community. The church's contact information is included on the back of the envelope.

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 blue ink. The message reads: "May their memories be a blessing." Color bleeding due to exposure to the elements at the Wilkins memorial.

Card from a congregant at the Holy Angels Parish. The front cover contains a stock illustration of a haloed dove flying in front of Noah's ark. Due to water exposure at the memorial site, the message in this card has been partially erased. The remaining text reads: "[?] everybody is ok...praying for those...are hurt and kill. [Na]me: Elio age: 10... [Holy Ang]els" CCD."

Post-it note with handwritten message in pink marker. The message reads: "Our hearts cry with yours for shalom." Signed with a heart, cross, and Star of David.

Post-it note with handwritten message in blue marker. The message reads: "You are loved. You are stronger than hate. Love and more love."

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." Signed "-Jenna [last name redacted]" in the lower right corner. The inside contains several messages, including: "We love [heart symbol] you... Get well soon!!!!... Get well soon... I'm praying for you...hope you get better...we hope you heal fast...get well soon.

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 with illustrated sunflower. Inscribed in ink with the following message: "Hate cannot break our Steel City." Signed: "equal [=] love [heart] Star of David."

Handwritten card from a student at Goddard Middle School in Littleton, Co. The front cover features the following quote: "Let your smile change the world but don't let the world change your smile." The inside reads: "Dear Tree of Life Congregation, I am very sorry for the bad news. I am a social studies student in Goddard Middle School. I know the feeling of losing someone, and it must be a very hard time for you guys. just so you know we'll be there for you guys and you'll always be in our thoughts. Sincerely, Evangeline."

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

Handwritten note from the [last name redacted] family from Toronto. Written in black ink on the back of stationary with the logo of Marriott Hotels. Staining due to exposure to the elements at the Wilkins memorial.

Card from a student at West Allegheny Middle School in Imperial, Pa. The front features a hand-colored illustration of the words: "I am here in this moment" as well as arrows and other geometric motifs; a handwritten inscription appears above. The back contains a handwritten note, as well as the stock signature: "From your friends at West Allegheny Middle School."

White envelope with blue border and curlicue designs in the four corners. Handwritten note in black ink on the recto reads: "Tree of Life Congregation." Staining and color fading due to exposure to the elements at the Wilkins memorial. The reverse side features a diamond pattern and has suffered from extensive tearing due to exposure to the elements at the Wilkins memorial.

Post-it note with handwritten message in blue marker. The message reads: "I'm praying for these holy souls, may God shine His light upon them!"

Letter from a member of the Point Loma Community Presbyterian Church in San Diego, California. The letter is dated 11/4/2018 and reads: "Dear Fellow Journeyers in Faith- May you experience others holding you in their caring arms during this time of loss and grief. Know you are not forgot. Know God can redeem this tragedy to bring about justice. -A friend in San Diego- Claudia."

Miniature New York State flag. Wrapped around stem of flag is a slip of laminated yellow paper reading, "In Memory of our Sister ROSE MALLINGER z''l -- To his family and community we pray Tanuchamo min hashamayim. May God in Heaven comfort you. The Principals, Teachers, Parents, Alumni, and Students of Magen David Yeshivah. Brooklyn, NY." Part of a series of 11 flags, each dedicated to one of the victims. Additional photograph shows the entire set of 11.

Handwritten card in pink marker on paper. The card contains illustrations of a flower and two hearts and reads: "Simon. May their memory be a blessing." Folded on the sides.