In September 1999, just weeks after a 46-year-old Vladimir Putin became Prime Minister, four bombs blew up four apartment buildings across Russia, killing hundreds of people while they slept. The attacks plunged the country into panic. Families fled their homes. Residents patrolled their blocks around the clock. An entire nation paralyzed by fear.

But who did it? It's a mystery that has fuelled some chilling theories.

The government blamed Chechen militants. Many reporters agreed. But then the whispers started. Was something even more sinister going on?

Over 25 years later, journalists who covered the bombings still can't agree on who planted the explosives or why.

Presenter Helena Merriman returns to the story with the reporters who were there on the ground. What did they get right first time around? And, in the chaos and confusion of unfolding events, what did they miss?