I've survived a gas explosion.
Reason why I will never use gas grills again.
For your comfort:
Fire only starts when 3 requirements are met: Oxygen, fuel and temperature. This happens often, but practically can't happen spontaniously.
Explosions occur when there is Oxygen, Fuel and temperature, along with a perfect proportion, this is even rarer.
Gas grills get such a lot of oxygen, and the pressure is so low (pretty much non excistent) that there is a microscopic chance of your gas grill exploding when properly used, especially since the fuel is nearly fully burned. practicly, you only get CO (carbon monoxide) explosions when there is inpartial combustion, which mostly only tend to happen in fires in confined spaces, when there suddenly is a surge of oxygen.
Trust me, I learned this in the FD, yo.