Five years ago: A presidential commission said the Obama administration had blocked efforts by government scientists to tell the American public just how bad the Gulf oil spill could become and committed other missteps that raised questions about its competence and candor during the crisis. Roy Halladay pitched the second no-hitter in postseason history, leading the Philadelphia Phillies over the Cincinnati Reds 4-0 in Game 1 of the NL division series. Social networking app Instagram, which enables users to share photos and videos on smartphones, was launched by Kevin Systrom and Mike Krieger.