Heard a bang from the garage and now the door won't lift? That's a broken torsion spring. Do not touch it, call a GDTS-certified tech.
Every year in Ottawa, homeowners get hurt trying to swap a garage door spring with hardware-store bars. A wound spring stores enough force to break bones. This job is not on YouTube, it's on a certified tech.
Most torsion spring jobs are done in under an hour once we're on-site, plus a full balance test and lubrication.