A 40-year-old man plowed his vehicle into a packed Mormon chapel Sunday morning, unleashing gunfire and flames that claimed four lives and wounded eight during worship, as police gunned down the suspect in the lot amid a frantic evacuation hailed as heroic.

Thomas Jacob Sanford, a Marine Corps veteran from nearby Burton, rammed the Church of Jesus Christ of Latter-day Saints around 10:25 a.m., firing an assault-style rifle inside before dousing the sanctuary with gasoline and igniting it, Grand Blanc Township Police Chief William Renye detailed at a tense presser.

Two victims succumbed to bullets, two more to the inferno; rescuers combed the charred ruins late into the night, with some still missing as the toll loomed. Hundreds had gathered for services when chaos erupted—Sanford's barrage shattered the calm, but congregants shielded children in back rooms, an act Renye called "pure heroism" that likely saved young lives.

Officers arrived in minutes, exchanging fire with Sanford, who fell at 10:33 a.m.; no cops were hurt.

Bomb squads swept the site, while state troopers cleared hoax threats at other locales, underscoring the rippling terror.

The FBI spearheads the probe as "targeted violence," sifting Sanford's phone and home for clues to a motive that eludes grasp, with U.S. Attorney General Pam Bondi decrying the "heartbreaking" assault on faith.

President Donald Trump, briefed swiftly, labeled it "yet another targeted attack on Christians," vowing federal muscle; Governor Gretchen Whitmer echoed the outrage, calling worship-site savagery "unacceptable."

The church, a pillar for its tight-knit flock, mourned in a statement: "We pray for peace and healing for all involved," as Mitt Romney—Utah's ex-senator and faith elder—joined pleas for solace.