How to fix a door that came off the track?

How to fix a door that came off track depends on whether it is garage door, sliding patio door, or interior sliding door, but general steps involve securing door, inspecting cause, and reseating rollers into tracks safely. For garage door that came off track with rollers out of vertical tracks, stop using opener, pull emergency release cord to disconnect trolley, and clamp door with locking pliers on tracks to prevent falling, as door weighs 150 to 300 pounds. If springs or cables broken, call professional as high tension dangerous, costing 150 to 350 dollars for off-track repair. If tracks only slightly bent, loosen track bolts, tap track back plumb with rubber mallet, and guide rollers back into track starting from bottom, with helper lifting door level. Tighten bolts and test manual operation. For sliding patio door that came off track, open door halfway, have helper support weight, lift door up into top track then swing bottom out, or reverse to reseat by lifting top into track first then setting bottom rollers onto bottom track. Clean track of dirt and debris with vacuum, inspect rollers for wear, and replace worn rollers costing 10 to 30 dollars. For closet bypass doors, lift door up and angle bottom out, then reseat. After reseating, adjust roller height screws for proper clearance and lubricate track with silicone spray. Keep tracks clean to prevent recurrence and avoid forcing doors.