My experience with Goodyear Marathon tires:


And here's my BIL's trailer:

I had a blowout with a Carlisle too.
The frustrating thing is there's NO visible warning. No cracks or bulges. Plenty of tire tread, and pressure checked the morning I roll out. Our trailer is a tandem axle, and WELL below the trailer rating, and same goes for the tire rating. I cruise at 63-65 MPH.
After hearing so many good things about Maxxis from people on the forums, and personal friends...

Problem solved.
I bought mine from here:
http://www.performanceplustire.com/Each tire was $100 (far less than local price), and shipping for all 4 was $19.95 total. I'm not affiliated with anyone, just pleased with the product, and source.