We consider an overlapping generations model in the presence of financial intermediation. The paper focuses on the analysis of the consequences of a sudden negative repayments shock on financial intermediation capacity and consequently on the economy as a whole. The model exhibits a property of the ‘chain reaction’ when a single macroeconomic shock can lead to the exhaustion of credit resources and subsequently to the collapse of the banking system. To maintain the capability of the system to recover, a regulatory intervention is needed even in presence of the state guarantees on agents’ deposits in the banks. We compare the results for an intermediated economy with those derived for the market economy and draw some broad conclusions regarding the crisis consequences depending on the financial sector structure. We also compare the model predictions with the stylised facts about the Russian financial crisis of 1998.