Tokyo has a 90 percent chance of being devastated by a major earthquake some time in the next 50 years, according to a recent study by a government panel.

The study marked the latest attempt by scientists to address one of this quake-prone country's most pressing concerns: When will the next "Big One" level one of the world's most densely populated cities?

Tokyo was last hit by a destructive quake in 1923 that toppled buildings, set the city aflame and led to the loss of at least 140,000 lives -- and experts warn it's overdue for another.