If airbags are deployed is it always collision related?

No, different cars have the airbag sensors positioned in different places and some sensors are more sensitive then others. Some cars only require a hefty kick to the front spoiler to set off the airbags or the Hollywood special of punching the dash board. Electric shorts can all so set them off, I have heard of mechanics dying from accidentally shorting out the airbag wiring when their heads were in a bad position. General rule of thumb is that orange wires are used to distinguish airbag sensor wiring from others but this could differ between makes and models.