Chevrolet 2004 Avalanche Owner's Manual page 37

CAUTION:
{
Never do this.
Here two children are wearing the same belt.
The belt can't properly spread the impact
forces. In a crash, the two children can be
crushed together and seriously injured. A belt
must be used by only one person at a time.
Q:
What if a child is wearing a lap-shoulder belt,
but the child is so small that the shoulder belt
is very close to the child's face or neck?
A:
If the child is sitting in a rear seat outside position,
move the child toward the center of the vehicle. If
the child is sitting in the center position, move the
child toward the safety belt buckle. In either case,
be sure that the shoulder belt still is on the child's
shoulder, so that in a crash the child's upper body
would have the restraint that belts provide. See
Rear Safety Belt Comfort Guides for Children and
Small Adults on page 1-27.
If the child is so small that the shoulder belt is still
very close to the child's face or neck, you might want
to place the child in a seat that has a lap belt, if your
vehicle has one.
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