Authorities in several cities are ramping up security in the wake of two explosions that rocked the Boston Marathon. New York City police added security to hotels and other major landmarks around the city, and security was also increased in near the White House in Washington, officials told NBC News. Jersey City's Police Chief said he was increasing security in all major transportation hubs, too, while Miami police did the same for areas deemed "critical infrastructures." Connecticut State Police reminded state residents to report suspicious activity, and Chicago police stepped up security at O'Hare International Airport. Both the San Francisco and Oakland police departments are telling officers to be extra careful in areas where large crowds gather, though they have not received any credible threats. Philadelphia police are assessing Boston's crisis, too, and will deploy personnel if necessary.