Come on let's go Garbage Truckin'

We're garbage truckin' round the stars  Come on let's go Garbage Truckin'. I was driving to work the other and I noticed a garbage truck pulled over on the side of the road. The driver had set up emergency flares and there was another garbage truck parked just in front. I can assume that one truck broke down but why the second truck? Did the driver call the other for backup? What were they doing now? Were they transferring the load?

A taxi driver or bus driver will call for backup if their vehicle breaks down. The passengers will quickly be off and on their way. A tow truck would be called to take the bus away.

I do not recall ever seeing a garbage truck being hauled away by a tow truck. 

What do you do with a broken down garbage truck? It is a garbage truck. I couldn't stay to watch but I am wondering if the garbage men just heaved the broken truck into the back of the second vehicle with all the other garbage.
That is why I am thinking they just get thrown out.