LANSING, Mich. (Michigan News Source) — When a gunman plowed his truck into a Mormon church on Sept. 28, worshippers weren’t just caught off guard by bullets and fire. The attack also exposed a softer target that safety experts say could have been strengthened long ago: the walls themselves.

Police say 40-year-old Thomas Jacob Sanford of Burton killed four people and injured several others after plowing into The Church of Jesus Christ of Latter-day Saints on McCandlish Road during Sunday services. Investigators also found explosives in his vehicle.

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Now, safety advocates are urging churches and businesses alike to rethink their defenses. Robert Reiter, co-founder of the Storefront Safety Council, told the Detroit Free Press that bollards, reinforced landscaping, or other barriers could make the difference between a near-miss and a massacre.

 “If an attacker can’t break into a building,” he said, “it’s going to attract a lot of attention.”

Crashes into buildings are not rare. Reiter’s group has tracked nearly 100 a day nationwide, most of them accidents—wrong pedal, drunk driver, or plain distraction—but many deadly. Gas stations commonly shield fuel pumps, and even Target’s signature red spheres outside its stores double as crash protection. Places of worship, however, often go without.

As police comb through evidence, the Grand Blanc attack has put new urgency on an old question: how to keep buildings, and the people inside them, safe.