Workers returned to 345 Park Ave., on Monday​ under the watchful eyes of NYPD officers and a surplus of security after the NYC mass shooting.

Twelve years after moving to the United States from Bangladesh, Didarul Islam sought to join the ranks of the nation's largest police department because he "got inspired" by the "blanket" of protection the NYPD provided to his community, according to an essay he wrote as part of his police academy application.

Workers returned to 345 Park Avenue in Midtown Manhattan under the watchful eyes of NYPD officers and a surplus of additional security. CBS News New York's Christina Fan reports.