HONOLULU -- The Coast Guard and authorities on Maui are trying to determine why the mast broke on a whale-watching catamaran, killing a 48-year-old man and injuring two others during a sail on Sunday evening.

It happened just after 5 p.m., about 3 miles off the west side of the Valley Isle.

Fifty-two people were on board the Kiele V when it happened, officials said.

The 55-foot catamaran is owned and operated by the Hyatt Regency Resort.

Two boats helped retrieve passengers from the catamaran.

Everyone else was rescued off the catamaran, which was left to sink, officials said.

The two who were injured were taken to a hospital in stable condition.

The Hyatt released a statement on Monday:

"We are deeply saddened by this accident and our concern is for those who have been affected by this tragic event. We are in direct contact with the Coast Guard and other authorities involved to understand how the accident happened. In the meantime, our attention is focused on attending to the people involved."