How did a bank bring down Paraguay President Peña in just 4 days?

Ex-Paraguayan President Santiago Peña was placed under house arrest after being impeached within four days of the collapse of Ueno Bank, which held savings of nearly half of the country's population. Peña was targeted over his previous role as a business partner in Ueno's owner Grupo Vázquez. Peña had appointed Ueno ex-CEO Carlos Carvallo as Paraguay's central bank chief.