What a terribly sad way to kick off this year’s Nationals home opener: longtime Philadelphia Philies broadcaster Harry Kalas — known for his signature “that ball is outta here!” home run call and soothing baritone — collapsed around noon inside the press box at Nationals Park. He was transported to George Washington University Medical Center, where, at 1:20 p.m., he was pronounced dead, according to a Philly.com report. Kalas, who had been the voice of…