Tonight on AC360: $50 million in diamonds gone without a trace

Like a scene out of a movie, eight masked men divided in two cars made a bold arrival through the perimeter fence of Brussels Airport for a fast and extraordinary robbery. The airport's spokesman said it took just minutes for the heavily armed group to get away with precious cargo – $50 million in rough and polished diamonds.

Despite airport security regulations, the thieves' plan to pilfer the jewels from a plane headed to Zurich, Switzerland went off without a hitch. No shots were fired and no one was injured. They carried out the heist about 25 miles from Antwerp, a heavily monitored city known as the world's diamond-cutting capital.

How did the robbers know about the diamonds? How were they able to choreograph the timing? Did the passengers on the plane know what was happening? And do the police have any clues?

Find out more about the story on AC360 at 8 and 10 p.m. ET.

UPDATE Watch Dan Rivers' report: