“The New York Nobody Knows: Walking 6,000 Miles in the City, chronicled Professor Helmreich’s experiences over four years — and many pairs of Rockports — walking virtually every city block, all 121,000, totaling 6,163 miles. Chatting with strangers, he unearthed a cornucopia of colorful city sidelights; he even once approached members of the street gang the Bloods outside a Bronx housing project and asked them where he could buy one of their red jackets.” A virus victim, William Helmreich, Sociologist and a Walker in the City, Dies at 74. (My next walk in NYC is for Helmreich.)