Rabbi Moshe Langer says Chabad of San Francisco first began active shooter training following the 2018 Pittsburgh Tree of Life Synagogue Shooting.
"This is survival, life or death," said Langer.
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Since then, the Poway synagogue shooting, machete attack in Monsey, New York and most recent hostage situation at a Texas synagogue have made security training continuously necessary.
Rabbi Langer says they train on a yearly basis. Grants have helped cover the cost.
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"We still have to make sure that this type of thing never happens again, and if it does happen we're well-trained and well-prepared and we have to use any means necessary to prevent any casualties," said Rabbi Langer.
One of the Texas hostages has credited taking an active shooter class with enabling him to survive.
Being prepared for the unthinkable has become a way of life for local religious leaders.
Rabbi Jason Rodich of Congregation Emanu-El in San Francisco says they have also been through active shooter training. He says he can't help but think of the danger while guiding congregants.
"I stand up on that bimah and at times think about my husband and daughter and worry what might happen... I keep going, I'm not going to stop. I have a community to serve, and I believe that we have to build the world that we want with love," said Rabbi Rodich.
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Emanu-El, known for it's open design, has been forced to put up walls where Rabbi Rodich says they'd rather not.
"It is truly so sad that we have to turn our congregation into a fortress. If you look at the design of the building, it was designed to be really open," said Rabbi Rodich.
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"I lament so much that we have to spend the resources on this, but also what it means for us spiritually to have to put up walls in a moment when we want so badly to be in a place of connection," he continued.
He says it's critical not to allow to this moment to lead to hatred against any other group in response.
As religious leaders comfort their congregants, they consider security training to be crucial to protect a space many gather to feel safe.