The original 2015 arc of astrometric observations for this object was only made over three days, so the orbit was extremely uncertain, with a range of close approach distances possible. Of course, the press will always hype the closest scenario to the max! In recent weeks the orbit has been refined and the closest approach is a LOT further away now, more like 3 million miles! The MPC table (scroll down to March 7) gives 0.027 AU and the NASA page (this page has two tables, recent and upcoming, which change daily and only go back a few days after the event) gives 0.033 AU. The two pages can be found at:
The MPC table lists LOADS of much closer approaches as you can see! In fact, two comets pass a similar distance from the Earth at the end of the month.