When a fan flipped over the railing and fell off the 21-foot-high Clemente Wall in right field at Pittsburgh’s PNC Park on Wednesday night, it elicited memories of fans who have died from similar falls at other major league stadiums. Kavan Markwood was in critical condition as of Thursday after falling onto the warning track in right field just as Pirates star Andrew McCutchen hit a two-run double in the seventh inning to put Pittsburgh ahead 4-3. Railing heights at ballparks are team decisions based on local laws and codes. The railing that runs along the Clemente Wall is three feet (36 inches) in height, which exceeds the building code requirements of 26 inches, according to Pirates vice president of communications Brian Warecki.