Other caused fire, don't they have to pay for it?

Someone, that we asked not to smoke in our truck, did, and tossed the butt out the window, it landed on the hay that was being hauled on the trailer they were hauling and it caught on fire and burned up several pieces of our landscaping equipment, straw, seed, and the trailer. It's going to cost over $8000 to repair and replace items. Our auto insurance doesn't cover this. Is that person liable for paying us for this?

Wow that's a good one.
Of course the butthead is liable. Hay, you told him not to smoke.
Then he wants to be a litterbug and tosses the butt out instead of using an ashtray. What a stupid ash.
Kick his butt and haul him into court.
Landscaping equipment is not cheap.