Toyota 1997 Corolla Owner's Manual page 34

However, this threshold velocity will be
considerably higher if the vehicle strikes
an object, such as a parked vehicle or sign
pole, which can move or deform on
impact, or if it is involved in an underride
collision (e.g. a collision in which the noise
of the vehicle "underrides", or goes under,
the bed of a truck.
It is possible with collision severity at the
marginal level of airbag sensor detection
and activation that only one of your ve-
hicle's two airbags will deploy.
For your safety, be sure to always wear
your seat belts.
30
The SRS airbags are not designed to
inflate if the vehicle is subjected to a
side or rear impact, if it rolls over, or if
it is involved in a low−speed frontal
collision.
The airbag sensor assembly consists of a
safing sensor and airbag sensor.
In a severe frontal impact, sensors detect
deceleration and the system triggers the
airbag inflators. Then a chemical reaction
in the inflators momentarily fills the air-
bags with non−toxic nitrogen gas to help
restrain the forward motion of the occu-
pants.