From CNN:

"Did the moon and sun conspire to sink the Titanic?
In a way, yes, researchers at Texas State University say.
Donald Olson and Russell Doescher, members of the physics faculty at the university in San Marcos, teamed up with Roger Sinnott, senior contributing editor at Sky & Telescope magazine, to determine how the iceberg the liner struck late on April 14, 1912, came to be in the North Atlantic shipping lanes. More than 1,500 people died when the liner sank less than three hours after hitting the berg.

The researchers theorize that the berg that sank the ship originated in Greenland and was stuck on the coast on Labrador or Newfoundland in early January 1912. Icebergs that become stuck there usually experienced significant melting before regaining enough buoyancy to float away from the coast.

But on January 4, the moon was near full and at its closest distance to the Earth in 1,400 years. A day earlier, Earth was at perihelion, its closest distance to the sun all year. The alignment of Earth, sun and moon created an exceptionally strong "spring tide" which could have refloated icebergs grounded on the northwestern Atlantic coast, the researchers said.
"It was the closest approach of the moon to the Earth in more than 1,400 years, and this configuration maximized the moon's tide-raising forces on Earth's oceans. That's remarkable," Olsen said in a university press release.
The website Titanic Facts reports that in April 1912 there were about 300 icebergs in the North Atlantic shipping lanes, the most seen in the route between Europe and North America in 50 years.

"As icebergs travel south, they often drift into shallow water and pause along the coasts of Labrador and Newfoundland. But an extremely high spring tide could refloat them, and the ebb tide would carry them back out into the Labrador Current where the icebergs would resume drifting southward. That could explain the abundant icebergs in the spring of 1912," Olson said in the release.

The abundance of icebergs that year would also be something the Titanic's experienced captain, Edward Smith, would not have predicted. He'd been sailing the North Atlantic for 26 years, according to Titanic Facts, and had not reduced the Titanic's speed despite receiving warnings of bergs ahead of his ship.

"The Titanic failed to slow down, even after having received several wireless messages warning of ice ahead," Olson said. "They went full speed into a region with icebergs. That's really what sank the ship, but the lunar connection may explain how an unusually large number of icebergs got into the path of the Titanic.""