1998 Toyota Corolla Repeated front wheel bearing failures

Left front wheel bearing has failed 3 times after 4000-5000 miles. All were installed as new parts by Toyota dealers (in 3 different cities!). Last repair included new axle. In each case car was driven mostly on highways at 60-70 mph. Have done alignment often. Little or no symptoms (grinding noise, steering wobble) before catastrophic failure. Before this series, right front wheel was damaged in parking-lot accident, but after replacing struts and straightening, no other symptoms on the right have occurred. I cannot think of any other part of the car that can cause such rapid and similar failures.