The 1st time, a container ship hit the Fitzgerald. It was a Phillipine ship, who path (shown in the link), is highly suggestive of it NOT having been an accident. Now, that might have meant just carelessness, not deliberate.
Remember what Goldfinger said.
“Mr Bond, they have a saying in Chicago: 'Once is happenstance. Twice is coincidence. The third time it's enemy action'.”