Longtime St. Paul residents Karen and George B. Benz who moved to Arizona about five years ago, are the largest single donors to the pediatric neuroscience center, which is under construction on the fifth floor of the hospital’s Sky Tower building. The $13 million center at 345 N. Smith Ave. is funded in part by $7.4 million in philanthropic support, and will soon bear their name. A previous George Benz — grandfather to George B. Benz — immigrated to the U.S. from Germany in the 1850s and established a liquor wholesale business in St. Paul in 1865. Benz, who died in 1908, served on the St. Paul School Board and in the state Legislature. His family sold off several Midwest liquor operations and diversified into real estate as Prohibition began in 1918. They remain active in the industry.