Tug Valour Sinking - What is the Cause??

Maritrans and its lawyers say they don't know why the Valour sank in heavy seas. They do say this:
Maritrans and the Coast Guard say they don't know what caused the 135-foot Valour to start taking on water around midnight Jan. 17 and go under 21/2 hours later. The weather turned nastier than expected when a surprise cold front passed through. But Valour was an ocean-going tug designed to tow barges in heavy seas. Two other tugs, including Maritrans' Independence, were sailing in the same area. "The weather was stronger than forecast," said Skip Volkle, legal counsel for Maritrans. "But it wasn't something where you could say (the tug) shouldn't be there."
Tugs like the Valour are "ocean going" and if they are seaworthy they should withstand this kind of weather. There will be Coast Guard hearings on this matter in March. The St Pete Times confrims this.
Dwayne Clark