In 2003 the Bolivian gas conflict broke out. On 12 October 2003 the government imposed martial law in El Alto after 16 people were shot by the police and several dozen wounded in violent clashes. Faced with the option of resigning or more bloodshed, Sánchez de Lozada offered his resignation in a letter to an emergency session of Congress. After his resignation was accepted and his vice president, Carlos Mesa, invested, he left on a commercially scheduled flight for the United States.