Captain James Staples, a longtime ship's master, instructor and maritime safety consultant, stated that Sunday's tragic sinking of the Leviathan II, a whale-watching ship off the coast of Vancouver Island, might have been caused by a fatal hull breach, reported USA Today.

"Something allowed the hull to fill with water because the weather wasn't that bad. This has to have been some form of sudden incident. My suspicion is that they got water in the engine room," said Staples.

The Leviathan II was on a routine tour when the accident happened. Currently, very few details about the incident are certain. However, the cause of the tragedy must have been grave enough to trigger the ship's immediate capsizing, according to the Mirror.

In fact, the ship sank so quickly that the crew was not even able to issue a distress call. They were able to alert rescuers by deploying flares while they were already in the frigid water, though.

The boat was carrying 27 people when it capsized. Though most of the passengers were successfully rescued, five people were reported to have been killed in the accident. A 27-year-old man from Sydney travelling with his British girlfriend has been reported missing.

The Leviathan II is owned by Jamie's Whaling Station and Adventure Centre, a company that has been in the whale-watching business for many years. The ship was said to be very well-maintained and manned by an experienced crew when the unfortunate accident happened.

For more news about the incident, click HERE.