Radiator failure ... 2000 MPV, 150k miles

My SIL has been telling me he suspected a radiator leak causing coolant loss. He could occassionally see coolant running down the radiator, he thought ... but wasn't sure. I told him if he kept on top of the coolant adds ... they could continue to drive until something more definite was determined. Was it the radiator or something else leaking?

So I got THE phone call the other day (I was overseas at the time): They had done a very good job of continuing to drive ... but a poor-ss job of adding coolant as needed. The engine was fried. So I am soon gonna start a rebuild ... and am not sure what was leaking!

I just wonder: Have any of you had any radiator failures on recent models?