A week after 35 million cubic feet of toxic sludge leaked out of an alumina plant reservoir in Ajka, Hungary killing seven people and creating one of the worst environmental disaster in European history, there are new fears this morning of another catastrophe. Four thousand workers and 300 machines are rushing to complete an emergency dam to prevent a second incident after new cracks were discovered in the reservoir's retaining wall.

All year long, people around the world have been recalling the events of 1989, 20 years ago, when the Soviet Empire in Europe collapsed, country after country.  They were generally known as "Velvet Revolutions": in Hungary, Czechoslovakia, East Germany, the fall of the Berlin Wall, the embrace of democracy all across central Europe, culminating with the final collapse of the Soviet Union itself, early in the 1990s. But shortly before Christmas 1989, the revolution came to the closed, bizarre dictatorship of Romania's Nicolai Ceauşescu ... and there, the revolution wasn't so velvety.  We talk with Nick Thorpe, BBC Central Europe correspondent and author of "'89: The Unfinished Revolution," from Opera Square in Timişoara, where the revolution happened 20 years ago.