Homeland security: NYPD lines Times Square; Times Square Twitter account tweets solidarity with Boston

In Washington, D.C., Pennsylvania Ave. has been shut down in front of the White House as a post-Boston Marathon bombing precaution.

In New York City, police are lined up at Times Square.

That's my building RT: @jorcohen: NYPD lined up in Times Square right now. pic.twitter.com/tjP50iGjZx

— Jim Herman (@jimgh141) April 15, 2013

All of our hearts are with Boston. The Times Square official Twitter account speaks for America.

Our hearts are in Boston. #StaySafe

— Times Square (@TimesSquareNYC) April 15, 2013