1915 New Orleans hurricane

As potential impacts on the United States became more clear, the Weather Bureau issued storm warnings for virtually the entire extent of the Eastern Seaboard from Eastport, Maine southward to the Florida coast on September 27.[10] Storm warnings for the Louisiana coast—where the hurricane would eventually make landfall—were first issued by the Weather Bureau on the morning of September 28 and disseminated via telegraph and mail. That afternoon, a hurricane warning was issued for coastal regions of the Gulf of Mexico from Pensacola, Florida to New Orleans, Louisiana. Extensive efforts to communicate the imminent threat the hurricane posed began in earnest following the issuance of warnings for the area, with public interests being advised that the approaching storm could be stronger than the 1909 Grand Isle hurricane, which served as New Orleans' strongest documented tropical cyclone at the time. Warnings continued into September 29, and local emergency offices enforced strict curfews for New Orleans as landfall approached; meteorologist Isaac Cline stated in an entry to the Monthly Weather Review that the effective dissemination of warnings and strict enforcement of curfew "unquestionably" mitigated additional loss of life in the city.[13]

As the hurricane traversed the Gulf of Mexico from September 28 to September 29,[2] it produced rough surf along its path. The cutter Miami was caught in the storm, but was able to use a heavily damaged ship as an anchor before resuming its trek towards Key West, Florida.[14]

Storm surge and rough seas produced by the hurricane along the Louisiana coast arrived shortly before the storm made landfall. Evacuees departing the coast as late as September 28 reported no abnormal tides along the shore. However, sea levels began to rise at abnormally rapid rates on the morning of September 29 as the hurricane neared. By the afternoon hours, low-lying lands south of New Orleans and east towards Bay St. Louis, Mississippi, as well as areas adjacent to Lake Pontchartrain, were inundated by the quickly rising storm surge. Levee overtopping along Lake Pontchartrain resulted in the flooding of much of western New Orleans. Parts of Carrollton, New Orleans were submerged under as much as 8 ft (2.4 m) of water due to the levee failure, and much of this inundation remained for up to four days as the city's drainage system slowly drained the floodwaters; in other locations, floodwaters receded rapidly. At its height, the surge was estimated to have crested between 15 and 20 ft (4.6 and 6.1 m) in height, setting a record for the highest tide reported in the region. Ocean swells topped levees along the Mississippi River and progressed well upstream; at the confluence of the Harvey Canal and the Mississippi River nearly 100 mi (160 km) from the Gulf of Mexico, the river swelled to 6 ft (1.8 m) above normal. Elsewhere, waves 10–12 ft (3.0–3.7 m) above normal high tide were reported along the same river.[13]

Upon making landfall, onshore anemometers documented winds stronger than had been recorded in any previous hurricane along the United States Gulf Coast. Gusts as high as 130 mph (210 km/h) were reported in New Orleans, with five-minute sustained winds peaking at 86 mph (138 km/h).[13] In Burrwood, Louisiana, a Weather Bureau anemometer documented peak five-minute sustained windspeeds of 122 mph (196 km/h), though when the abnormally high bias of the era's anemometers and adjustment to the more standard one-minute sustained measure are accounted for, this yields a speed of 99 mph (159 km/h).[1] The intense winds caused extensive damage across New Orleans, where nearly every building sustained damage.[13] The French Market was partly demolished, while the roof of a prominent Masonic temple partially collapsed.[15] Combined with powerful waves, the winds resulted in the sinking of four small steamers at the Port of New Orleans, in addition to several coal barges. A number of other steamers and small craft were blown from bayous and bays onto dry land.[13] The winds also caused widespread power outages, cutting telecommunications to and from the city,[16] and putting over 8000 telephones out of commission. Electric lighting was also disabled by the storm following the failure of city's power station.[15] Damage to city-owned property in New Orleans was appraised at nearly US$500,000, though the total amount of damage to all public and private property in the city was estimated to have been at least ten times greater at US$5 million. Damage to shipping along the Mississippi River in and around New Orleans was estimated at US$1.75 million.[13] Following the storm's passage, rail service to New Orleans was suspended.[15]

Roofs were blown off buildings and the Presbytère on Jackson Square lost its cupola. The clock on St. Louis Cathedral stopped at 5:50pm, the height of the storm. The hurricane damaged the Times-Picayune building, hampering newspaper production. More church steeples in the city were blown down or significantly damaged than remained intact.[17]

First Presbyterian Church on Lafayette Square, destroyed by the great hurricane of 1915, collapsing at 5:02pm.[18]

The landmark Presbyterian Church on Lafayette Square collapsed, as did St. Anna's Episcopal Church on Esplanade Avenue. Half the rides at Spanish Fort were destroyed. Horticultural Hall in Audubon Park was destroyed. Wind damage was worse than the most recent previous hurricane to hit the city in 1909, but flooding was much less widespread; however, there were reports of waters from Lake Pontchartrain being forced backwards into the city's drainage canals by the storm, an event which would be repeated more catastrophically with Hurricane Katrina 90 years later. After power to drainage pumps failed, parts of the Mid-City neighborhood suffered significant flooding. Only 21 of the storm-related deaths were within the city.

The hurricane also caused significant damage in areas around New Orleans, including the destruction of 90% of buildings destroyed along Lake Pontchartrain. Only one house remained standing in Leeville, Louisiana; similar destruction occurred between Golden Meadow, Louisiana and Cut Off, Louisiana, where 100 houses were demolished.[13] In Morgan City, Louisiana, winds of 75 mph (121 km/h) blew down wires and crippled communication.[19] The total damage to infrastructure in areas surrounding New Orleans was estimated at US$6.5 million. The heaviest rain fell within an area 25 mi (40 km) east of the center, though heavy rainfall occurred throughout the eastern half of the tropical cyclone as it moved inland.[13] Franklin, Louisiana measured the highest rainfall associated with the storm with a reading of 14.43 in (36.7 cm); on September 30, 10.28 in (26.1 cm) of rain fell in Franklin, setting a September 24-hour rainfall record for the city.[4] Precipitation spread ahead of the hurricane as it interacted with a stationary front draped over the Southeastern United States, causing widespread rainfall totals in excess of 3 in (7.6 cm) across much of Mississippi and Alabama.[5] A 13-foot (4.0 m) storm surge rolled into St. Bernard Parish, the Rigolets, and the Lake Catherine area.

Areas along the Lower Coast (south of New Orleans) were hit even harder than the city. A telegraph report states the situation:

Whole country between Poydras and Buras inundated. Levees gone, property loss appalling. Life toll probably heavy. Conditions estimated worse than ever before. Relief needed. No communications...

There were 23 dead in Venice, Louisiana, with similar numbers in coastal towns of Frenier and LaBranche. Plaquemines Parish experienced the worst fatalities with deaths estimated at over 200; the bodies of some victims were never found. In Plaquemines Parish, there was severe flooding and miles of levees were washed away. Thousands of people were left homeless. The hurricane also wrecked many of the oyster boats, damaging the local economy.

Some communities, including Breton Island and the town of Saint Malo, were completely destroyed.

Though it was not as deadly as the 1893 Chenier Caminanda hurricane, this hurricane was the deadliest Louisiana hurricane until Betsy 50 years later.

Early reports that streets in Biloxi, Mississippi were inundated under 6 ft (1.8 m) were initially denied by Louisville and Nashville Railroad dispatchers. Mobile, Alabama did not experience significant damage as winds remained under 50 mph (80 km/h), though storm surge A local train carrying relief supplies from Mobile was sent to affected areas, though most train service in the region was suspended.