BMW air bag deploys while car is parked and unoccupied?

Can a high temp inside a car cause a curtain air bag to deploy while it is parked ?
It happened to my daughter’s BMW 535xi…I believe its a 2008 or 2009…it was parked in the campus lot and when she came out of class to her car, the airbag was deployed and her front windshield cracked in a spider web shape starting at the top drivers side corner…no other damage was present on the car at all…campus police said maybe it was a fluke and the heat caused it…but it was only 103 degrees today and we have been having 112 degree days for the last month, so today was cool in comparison…what could have happened ?
thanks…Dallas, Tx

these are pics of the car…I would think if someone hit the car hard enough in the parking lot to cause the air bag to deploy there would be a scratch or some type of damage to it…could heat have caused this ?

I have heard of cases where the bump did not leave a scratch, but did pop the bag(s).

Has your insurance company inspected the car? They may be able to determine if it was a hit and run, even if you can’t see any damage.

Bumper covers are somewhat flexible, so it seems to me that you could give a car a decent jolt without leaving a mark. When I was rear-ended last year by a girl on a cellphone, there was only one small mark that rubbed out by hand, although the hit wasn’t hard enough to trigger any airbags.

I suspect you’re in a tough position as far as insurance and warranty coverage (if any). BMW will probably claim there was a collision and the insurance company will probably claim there wasn’t. I wonder if you could see any damage if the bumper covers were removed. Do you know if there are any security cameras covering the lot?

If the airbag did go off by itself, I’d be nervous about driving the car unless all sensors were replaced, which is likely a terribly expensive job on a BMW. Otherwise it could happen again while she’s driving.

Side airbag only…
Look for evidence on the rear bumper on that side.
Being a parking lot setting I can see someone mis-judging their angle entering the space beside and whacking the rear corner.

If a car’s air bag system told the air bags to deploy, wouldn’t all of them go off? Also, I believe most cars have some type of event recorder computer on board. The dealer might be able to tell if the system fired the air bag and why.

I Googled “BMW airbag deployment” and found multiple entries on air bags that went off with no reason or after hitting a pothole. Sounds like there may be a problem at BMW’s end.

BMW should have no problem fixing this under warranty. The airbags should not go off with the car switched off, no matter how hard it is hit.

A parked car that is turned off should never have a air bag deploy. There are a lot of factors that are involved for a air bag to deploy. This was caused by a malfunction of the air bag system. The air bag system is not armed in till a set speed is reached and most new cars (if not all) now have a sensor in the seat. If no one is in the seat it wont deploy. You can not just bump a car and have the air bag deploy unless the system is malfunctioning. Heat can not and will not deploy a air bag. If that was the case when I would bake a car after painting it they would be going off all the time.