[Bahbah]

Is it to keep them from flying away or to support the walls.

My best guess is that it has nothing to do wth supporting the walls. Rather, it keeps these things from ripping loose or falling over during the storm or quake. Just my guess.

[Lanza]

FYI to anyone in Clear Creek School District. School is canceled for tomorrow. Check it out at ccisd.net
My son is sick and I emailed the teachers for homework, and they said school is cancelled for Wednesday,Thursday.

[laz]

Rather, it keeps these things from ripping loose or falling over during the storm or quake.

Yes. Remember, the Katrina advisory just before landfall in LA warned about appliances flying through the air and killing people outside.