The Pearl Street Mall on Sunday afternoon was so picture perfect — a bluebird sky, Boulder shoppers dipping in and out of brick buildings, children playing in a splash pad — that bystanders didn’t recognize the first flashes of flame as dangerous.

Edgar Depaz, 35, saw fire burst from a gardener’s weed sprayer and assumed it was an accident, that the man’s equipment was malfunctioning. Chloe Weber, 41, visiting the splash pad with her son, thought someone had self-immolated in protest. Lynn Segal, 72, heard the rush of fire and thought of the entertainers who sometimes perform on the mall. Rick Holter, 63, assumed someone was burning a flag in protest.

The blaze did not invoke the same gut-dropping panic of gunshots in a crowded public square. Even the sight of a shirtless man, holding tw

See Full Page