Nitro 28 foot enclosed car hauler trailer. 2-7000 lbs. Dexter torsion axles. The axles are mounted by inserting a hex head bolt in an aluminum "T" slot. While driving cross country at (approx) 6500 miles the axles came out from under the trailer. The trailer is currently at my residence and can be seen upon request. If the failure happened on the highway or one of the mountain roads we traveled someone could have died in the accident. The problem has not been reproduced or confirmed by a dealer. The manufacture stands behind their method / design that is not the recommended mounting method by Dexter. The trailer has not been inspected by the manufacture, I feel they want to quietly sweep this aside. Their warranty covers the repair but they claim no responsibility. There were no prior warnings that the axels mounting was failing.