WASHINGTON — Demolition began Monday on the East Wing of the White House to make way for President Trump’s massive new $250 million ballroom. Photos provided to The Post show that construction crews have already ripped off the covered entrance that for decades greeted visitors going on tours or attending special events. Windows facing the Treasury Department are smashed and half-off their hinges and the former upper-floor White House calligraphy office bears a gaping hole. Video that circulated after the photos were snapped shows a large demolition machine reaching well into the structure to pull out rubble as a hose sprays water to minimize dust.