Manufacturing and retail remained Wilkes-Barre's strongest industries, but the city's economy took a major blow from Tropical Storm Agnes in 1972. The storm pushed the Susquehanna River to a height of nearly , four feet above the city's levees, flooding downtown with nine feet of water. A total of 128 deaths were attributed to the storm. Most drowning deaths were caused by people trapped in their cars. Almost 400,000 homes and businesses were destroyed and 220,000 Pennsylvanians were left homeless (as were hundreds of thousands in other states). Damage was estimated to be $2.1 billion in Pennsylvania alone. President Richard Nixon sent aid to the area, after flying over in his helicopter on his way to his Camp David retreat (on June 24, 1972).