After the shooting in Las Vegas and a Monday night shooting in Lawrence, Kansas, students at the University of Kansas were feeling especially vulnerable.

“On Monday three students called me and said that they’re not going to class because they felt afraid and vulnerable,” Rabbi Zalman Tiechtel, cofounder of the local Chabad House, told the university newspaper.

In response, students have worked with the rabbi to launch a “random acts of goodness and kindness” campaign, passing around cards that instruct the holder to do a mitzvah within 10 minutes before passing the card on to a friend. The goal? To spread 5,000 such cards around the campus and city. The cards, students say, encourage people to reach out to others and “get involved in the community and help people.”