Description: The explosion in one of the four reactors of the nuclear power station at Chernobyl on April 25, 1986, was an ecological accident on a continental scale. The radioactive pollution first crossed the frontier with Belorussia, then entered rain clouds, thus contaminating all of northwestern Europe. The extent of the disaster found expression in the popular saying that arose at the time, ôRare is the bird that can cross the Pripet River.ö It echoes the helplessness felt by the population after the strong radiation that affected the Pripet, a 775-kilometer- (485-mile-) long navigable branch of the Dniepr River on which the power station was built. Entire villages were evacuated when a safety zone was established around the station. It is not unreasonable to be concerned about nuclear power stations elsewhere. Some, such as those in Turkey, are in areas prone to earthquakes; others, as in France, are in flood zones. But the Chernobyl catastrophe was caused by massive human error. Human actions can be more dangerous than either nature or technology, and technology greatly amplifies the consequences of our mistakes.