Forty years later, the impact of Hurricane Agnes is broad-ranging.
And for those who lived through it, Agnes is the barometer by which all of today's hurricanes and tropical storms are measured.
In other words, there is only one Agnes, the hurricane that arrived in Williamsport 40 years ago this coming Thursday.
Agnes brought torrents of rain for days, with water that overran residential and business districts in municipalities throughout the region. There was death, damage and destruction that left a timeless stain as waters recessed in weeks after the flood.
In the region's population and commerce center, Williamsport, Agnes underscored the value of a dike system that was built after the flood of 1936 ravaged the city. In 1972, while surrounding areas were overrun with floodwaters,
Williamsport was saved by inches from a similar fate.
The waters rose so close to the top of the levy along the Susquehanna River at Williamsport southern edge that sandbaggers could touch them. But the levy held and Williamsport was spared the greatest damages.
Other municipalities were not as lucky and there was tragedy, some of it due to a lack of preparedness. In the wake of Agnes, the modern flood warning system was established and has since been refined through a combination of improved technology and improved coordination among municipalities and emergency officials.
It's hard to remember anything different, but when a flood-carrier hits today, such as Tropical Storm Lee last September, the game plan of evacuation and protection is in place days ahead and the public is fully aware days ahead.
We can't stop everything these tragedies bring with them, but we can limit the harm with preparedness.
And it's fair to wonder if all the increased consciousness about flooding, its prevention and the safeguards to blunt its impact would be in place if it weren't for the events of 40 years ago.
Because, it's worth repeating, there is only one Agnes.