 He briefly returned to Pottsville and then moved to "The Philadelphia Inquirer", covering medical economics on the business staff.In 1989, Gaul wrote a five-part series on the business of buying and selling human blood, as well as safety flaws in the nation's blood system.The "Inquirer" won the 1990 Pulitzer Prize for Public Service citing "reporting by Gilbert M. Gaul that disclosed how the American blood industry operates with little government regulation or supervision."