I've driven semi's for 18 years and it is rare to have an actual air bag leak. Normally you see a wear mark before the bag develops an issue. Normally it's the air leveler valve that goes bad or a bad fitting. Limp it home or a safe place and call road repair. The one time I had a bad bag, they isolated it to stop the leak and I limped the 20 miles back to the yard.
If it did not cost about $4k to do it, I'd swap out the leaf springs in my F350 for air ride suspension in a heart beat. Whenever I do replace my current truck I will be looking for air ride.