Two high water markers on the northeast corner of the Rhode Island Hospital Trust Company building on Memorial Boulevard at Westminster Street show the flood levels of the Gale of September 1815 (lower) and Hurricane of 1938 (upper). Location is immediately along the Providence River. There are more markers to be found on nearby buildings as you head west along Westminster Street, too.
Brown University shares photographs and retells history of the events in an essay, Remembering Providence's Hurricanes, part of which is below:
Originally known as “gales,” hurricanes targeted Providence as early as the mid-18th century. The first was recorded to have swept ashore on October, 24th 1764. The storm was reported to have caused the highest tide in recorded memory, and destroyed everything in its corridor, including the famed Weybosset Bridge.
The Great Gale of 1815 raised a tide of 11 ft, 9 ½ inches above mean highwater. The storm swept across Rhode Island, destroying innumerable houses, barns, and nearly all the building wharves along the coastline. Reports indicated that every vessel in the harbor was propelled from its moorings. In downtown Providence, the bowsprit of the ship Ganges inflicted damage as high as the second story of the Washington Insurance Building. The storm dismantled the Second Baptist meeting house, though it only slightly damaged the still-standing First Baptist meeting located on higher ground.
The September Gale of 1869, newspapers reported, was nearly as bad as that of 1815, though less is known of its damages.
The first gale of the twentieth century, dubbed the “Great New England Hurricane,” landed on September 21, 1938. This massive storm moved swiftly and powerfully up the Atlantic Coast, picking up force all the way, and eventually touching down on New York’s Long Island. But it certainly did not stop there. In fact, it saved its greatest devastation for New England, most especially for the Providence area. When damages from the storm were eventually tallied, estimates topped nearly 100 million dollars, an astonishing total for the time period. It is still considered perhaps the worst disaster in Rhode Island history. Some two hundred and sixty two people were killed across the state. Low-lying downtown Providence was the site of many particularly horrifying scenes. Nearly every building saw water up to its first story, and several people perished before even being able to escape their automobiles.