I had this happen twice at my old house. The eyes of the springs develop
fatigue cracks over time, and when the crack propagates deep
enough....BAM!!
The best solution is to get new garage doors with torsion springs on
them.

If you don't want to do that, then replace all the springs so they are
the
same age and have the same number of cycles on them. Replace every 5
years
or so before the have a chance to break.- Hide quoted text -

- Show quoted text -

- The best solution is to get new garage doors with torsion springs on
them.

While a torsion spring may not let go with the force of an extension
spring, they do present a different kind of danger.

Huh? How does a torsion spring present a 'different danger' than a
extension spring?
The incident you describe could have just as easily happened with an
extension spring door
with an opener on it. You should not have pulled the emergency release with
children present!
Glad your daughter is OK!