Overloaded? Nah, it's a truck. It can handle it, right?

One day as I was leaving my parents home a P/U went by with a load of sod that went a little above the cab. I debated about calling police in the next town but didn't. We left 10 minutes later and passed where he was stopped along the road with smoke coming from the rear of the truck. I think the tires had rubbed until they got so hot that they started smoking.