Mallory Kasdan with her father, Richard Kasdan, in Pittsburgh in 1985, after her bat mitzvah at Tree of Life synagogue. (Family photo) (N/A/Family photo)

The nostalgia around childhood is powerful. At 46, I can visualize my kindergarten cubby and rainbow-colored mat, feel the pebbly summer-camp road under my feet and hear the conspiratorial giggles of my friends gossiping in the girls’ room of my childhood synagogue.

Now that place is one of the most blood-soaked crime scenes in Jewish American history.

Some of the most visceral moments of my life revolve around Tree of Life synagogue in Pittsburgh’s Squirrel Hill.

I remember the carpeted steps of the bimah, or stage, in the sanctuary leading up to the Torah. I proudly walked those stairs in my powder-pink flats in 1985 to read my assigned section of scripture on my bat mitzvah, and again (in different shoes) in 2013 to give my mom’s eulogy after we lost her to cancer. I remember looking out, lost, at the rows of people and then feeling their support holding me up.

I knew, in a primal way — the way you can almost physically feel the comfort and familiarity of a place — that Tree of Life’s roots were in me. But I understand in a new way today the responsibility of those roots.

As a young child fidgeting through High Holiday services, I remember well the physical room — the blond wood pews, imposing floor-to-ceiling stained-glass panels and Andrew Lloyd Webber-ish organ. The tall-backed, upholstered seats on the bimah, brimming with people honored to have aliyot, the Hebrew word for the honors given to people who participate in the service.

I can envision the men’s heads, with the different hair patterns and the ways their kippots would cling to those heads. The women, embracing their Eastern European, curly-moussed ’80s hair, and later, in the 1990s, the stick-straightened hair so many Jewish women coveted almost in spite of their follicular tendencies. The older bubbies, or grandmas, who had made it to the local beauty parlor that week. Maybe we had even seen them at the David Weber Salon on Forbes Avenue, less than a mile away.

I remember the whispering, the shushing, and candy wrappers, and the murmurs and kind looks of approval from some of the older congregants as our family walked down the aisle to our seats.

That room, now a modern-day horror scene, is one that presents new questions for me as a Jewish parent.

Reading today about congregants hiding in closets and offices and classrooms where I spent formative years learning, singing and socializing is excruciating. I can picture it all.

I can picture Cecil and David Rosenthal, the brothers who were at every Shabbat service. They were probably at my bat mitzvah, probably at my mom’s memorial service, and they were there Saturday. With intellectually developmental disabilities, they were especially trusting and vulnerable.

I remember once getting sent to the principal’s office during Hebrew school. That principal, David Dinkins, was and is the kindest man, a stalwart of the community and always, always in shul, or synagogue. He is 95 years old and stayed home Saturday from services.

I remember leaving home for college, and my mom getting involved in the synagogue’s annual play. She and her friends really did have a fabulous time putting on those productions.

I will always be grateful to the congregation for giving my father a place to say the kaddish, or mourner’s prayer, for my mom, and for honoring him at High Holiday services.

As an adult, with school-age children in religious school at our synagogue in Brooklyn, there are similarities to Tree of Life, and to Jewish congregations around the world. Sometimes I have asked myself: Am I sure why we still go? In recent years, I have been coming to recognize why these physical spaces are so crucial. But I saw something different this weekend.

On Saturday night, absorbing the news of the shooting in my childhood synagogue, an attack on my community, my religion, my very being, it was clarified. It is urgent that we keep going, keep worshiping together, learning and discussing and arguing and thinking.

I was talking to my daughter about the upcoming week’s schedule, and I mentioned to her that we had a meeting at our synagogue Tuesday evening to talk about her upcoming bat mitzvah.

“Ugh,” she said.

Which she says, sometimes, because she’s 12. I remember similar conversations with my mother.

“Do you understand what’s happening?” I snapped in my serious-mom voice. “People hate us just for being us. We must understand and acknowledge this, and keep practicing our Jewish rituals. The time will come when we will need them. And we will need them."

This sudden, new stream of words came from my gut and was intense, this feeling I had of obligation and the need for my daughter to understand why we go, even if we don’t always feel connected to prayer and it isn’t always pleasant and we can’t always point to why. Living our Jewish lives is not just a privilege we opt in or out of, I see more clearly now.

I hope with all of my heart that our children can have their own nostalgic feelings of safety and community. I hope they will be able to hold on to that peaceful, unafraid Judaism in which they were raised.

But they must know more than that. We all must. We must root out hatred and figure out how we can be engaged in staying safe and protecting these institutions. Now is the time to act. To be there for each other, to be active in our political process, to vote and show our children the way. The best way. The way of love and peace and inclusion and support for those who need it.

The next afternoon, I took my daughter to a vigil in Brooklyn with friends and neighbors and so many who maybe, like me, are looking in a new way at that tree. Together we stood and sang “Oseh Shalom,” the classic Jewish ballad. Oseh Shalom, make peace, make peace.

Mallory Kasdan is the host of the MILK (Moms I’d Like to Know) Podcast. She grew up in Squirrel Hill.