The door has suddenly gone heavy, will not lift, or drops fast when you try it
Why it happens
The springs counterbalance the weight of the door so the opener, or your arm, only has to do a little of the work. When a spring goes, that whole weight lands somewhere else.
Why it matters
A garage door manufacturers' association describes doors as large, heavy moving objects that can weigh anywhere from 90 pounds to over 500 pounds, so what was being carried for you is not a small load.
Response
Thom takes the load off safely and gets the door back on its track. On a two-spring door it is usually worth doing both, because they wear at the same rate, so if one has gone the other is not far behind.




