Maybe it wasn’t just the iceberg.

Ever since the Titanic sank more than 104 years ago, killing more than 1,500 men, women and children, mystery has swirled around the tragedy.

No one doubts that the ship collided at high speed with an iceberg off the coast of Newfoundland.

But a new documentary posits that the sinking of the ship — hailed at the time as the largest ever built, and praised for its professed unsinkability — may have been accelerated by a giant coal fire in its hull that appeared to have started as long as three weeks before it set off on its fateful journey to New York from Southampton, England.