PHILADELPHIA (AP) -- Top officials in Philadelphia hope that Pope Francis will attend a huge Roman Catholic gathering planned for the city next year. Archbishop Charles Chaput (SHAP'-yew), Mayor Michael Nutter and others will visit Rome this month to invite the pope to the eighth World Meeting of Families. The September 2015 event is expected to attract more than one million people from around the world. At a news conference Friday, Chaput said he will lead a delegation traveling to the Vatican from March 23 to 27 to plan the event. The group, including Pennsylvania Gov. Tom Corbett, will also meet with the pope. Corbett says the six-day event will also pump $100 million into the Philadelphia region's economy. The World Meeting of Families was last held in Milan in 2012.