The "unsinkable" Titanic was sunk by an iceberg, but there are other reasons why the tragedy that occurred 100 years ago this month was as tragic as it was. Even a century later, the case of the Titanic illustrates how technological failures often result from a succession of omissions, missteps and bad luck rather than one big mess-up.

"No one thing sent the Titanic to the bottom of the North Atlantic," Richard Corfield writes in a Physics World retrospective on the disaster that caused 1,514 deaths on April 14-15, 1912. "Rather, the ship was ensnared by a perfect storm of circumstances that conspired her to her doom. Such a chain is familiar to those who study disasters — it is called an 'event cascade.'"

The iceberg that the Titanic struck on its way from Southampton to New York is No. 1 on a top-10 list of circumstances. Here are nine other suggested circumstances from Corfield's article and other sources:

Climate caused more icebergs: Weather conditions in the North Atlantic were particularly conducive for corralling icebergs at the intersection of the Labrador Current and the Gulf Stream, due to warmer-than-usual waters in the Gulf Stream, Richard Norris of the Scripps Institution of Oceanography told Physics World. "Oceanographically, the upshot of that was that icebergs, sea ice and growlers were concentrated in the very position where the collision happened," Norris said.

Tides sent icebergs southward: Last month, astronomers at Texas State University at San Marcos noted that the sun, the moon and Earth were aligned in such a way that could have led to unusually high tides in January 1912. They speculated that the tides could have dislodged icebergs that were stuck in the Labrador Sea, sending more of them toward the waters traversed by the Titanic a couple of months later.

The ship was going too fast: Many Titanicologists have said that the ship's captain, Edward J. Smith, was aiming to better the crossing time of the Olympic, the Titanic's older sibling in the White Star fleet. For some, the fact that the Titanic was sailing full speed ahead despite concerns about icebergs was Smith's biggest misstep. "Simply put, Titanic was traveling way too fast in an area known to contain ice; that's the bottom line," says Mark Nichol, webmaster for the Titanic and Other White Star Ships website.

Iceberg warnings went unheeded: The Titanic received multiple warnings about icefields in the North Atlantic over the wireless, but Corfield notes that the last and most specific warning was not passed along by senior radio operator Jack Phillips to Captain Smith, apparently because it didn't carry the prefix "MSG" (Masters' Service Gram). That would have required a personal acknowledgment from the captain. "Phillips interpreted it as non-urgent and returned to sending passenger messages to the receiver on shore at Cape Race, Newfoundland, before it went out of range," Corfield writes.