
Almost always a defect that existed before the storm: a root plate that tore out of saturated ground during a summer downburst, or a stem or branch union that failed at included bark or an old decay column. Winter version is ice loading adding several times a limb's own weight.
A trunk or major limb resting on the roof, punched through it, or hung up on the gutter and eave. Inside: ceiling stains spreading, drywall sagging or popped nails, doors and windows that suddenly won't latch, daylight visible in the attic, displaced shingles. The tree often looks completely settled and still — that appearance is not information.