GMC Sierra Classic 2007 Owner's Manual page 49

CAUTION:
{
Children who are up against, or very close
to, any airbag when it inflates can be
seriously injured or killed. Airbags plus
lap-shoulder belts offer protection for
adults and older children, but not for
young children and infants. Neither the
vehicle's safety belt system nor its airbag
system is designed for them. Young
children and infants need the protection
that a child restraint system can provide.
49