On an assignment that I have, the garage door will not fully go down. There's enough space for someone to stick both there hands underneath and pull it up. Tips on how to temporarily get this fixed.

I had the same problem one of mine,well actually 2. What I did was lock the door leading from garage inside to home. LOL
Well, I one I actually tried to straighten out the bent rail and then after that did not work I pulled hard and it was able to shut, but if I let go it would pop up again. So what I did was hold it down and wedged a piece of wood in between so it would stay closed. Only short term solution.

Just thought of something. I'm going to use zip ties. I was thinking of buying some chains but zip ties are probably just as effective.

This is going to sound very simplistic, but it works.
Take a chain & padlock or even a spring clamp. Usually the verticle part of the track has some holes cut out. Put the chain & padlock or clamp through the lowest hole. No one should be able to open the door.
I do this when I go on vacation, even though the automatic garage door opener should keep the door down. It will take a really strong person to force open the door.

Check out the track, see where it's binding... probably a job for a big old vice-grip... but bring a hammer and that huge screwdriver nobody ever uses for screws with you too.

Yeah I use padlocks in the tracks so it cant be lifted open.

Yeah I use padlocks in the tracks so it cant be lifted open.