Power has been restored to much of Sao Paulo and Rio de Janeiro in Brazil after the two cities experienced four hours of electrical blackout. The power outage, apparently caused by transmission problems at a hydroelectrical station at the Itaipu dam, also briefly affected neighbouring Paraguay and, for longer, nine of Brazil’s 27 states. MCNBC reports that the dam is the world’s second largest, after China’s Three Gorges dam. The blackout is raising concerns about the country’s management of its electricity infrastructure, with recent accusations that earlier accusations that smaller blackouts have been caused by hackers, and with worries that power problems could be a problem in the runup to the 2016 Olympic Games.

Links to other sites: BrazzilMag, MSNBC, Shanghai Daily