The storm killed at least 469 people in Haiti before it struck the United States near the border between North and South Carolina as a Category 4 hurricane.

After causing 95 fatalities in the US, Hazel struck Canada as an extratropical storm, which raised the death toll by 81 people, mostly in Toronto.

As a result of the high death toll and the damage caused by Hazel, its name was retired from use for North Atlantic hurricanes.

The effects of Hazel were particularly unprecedented in Toronto because of a combination of heavy rainfall during the preceding weeks, a lack of experience in dealing with hurricanes, and the storm's unexpected retention of power despite traveling 1,100 km (680 mi) over land.

Due to the potential for tropical storm formation, a Hurricane Hunters plane flew from San Juan, Puerto Rico, to investigate the system.

[1] When the plane reached the system, they observed a tropical cyclone about 30 mi (48 km) east of the island of Grenada with winds estimated at 100 mph (160 km/h).

[2] The Atlantic hurricane reanalysis later assessed that Hazel developed at 06:00 UTC on October 5 about 220 mi (350 km) east of Grenada.

Although the Hurricane Hunters observed hurricane-force winds, the storm had a small eye 5 mi (8.0 km) in diameter and a central barometric pressure of 1,002 mbar (29.6 inHg).

[4] For the next five days, there were no further flights into the core of the hurricane; However, the planes continued to monitor the storm, with radar imagery indicating that the eye became open and ragged.

[3] On October 10, Hazel slowed in the central Caribbean and turned sharply to the north-northeast toward Hispaniola,[3] steered by an upper-level low.

After moving through the Gulf of Gonâve, Hazel struck northwestern Haiti near Baie-de-Henne at 00:00 UTC on October 13, as a Category 2 hurricane with winds estimated at 100 mph (160 km/h).

[7] The Hurricane Hunters were unable to observe the core of the storm until it neared land, reporting an eye 18 mi (29 km) in diameter on October 15.

Later that day, a ship just off South Carolina reported a central pressure of 938 mbar (27.7 inHg), which was the lowest in association with the hurricane.

At 15:30 UTC on October 15, Hazel made landfall just west of the North Carolina/South Carolina border with a 40 mi (64 km) eye, slightly northeast of Myrtle Beach in the latter state.

Based on the pressure, a larger than average size, and the fast forward movement, the landfall intensity was estimated at 130 mph (210 km/h), or a Category 4 on the Saffir-Simpson scale.

After turning to the northeast, into what is today known as the Kativik region of extreme northern Quebec, the remnants of Hazel were absorbed by a larger extratropical storm over Canada on October 18.

[9] After the storm turned northward, tropical cyclone warnings were posted for Haiti, the Dominican Republic, and the waters of the Mona Passage.

[11] The U.S. Navy completed extensive preparations at its Guantanamo Bay base, ordering about 1,000 civilians into hardened, fortified Quonset huts, flying aircraft out of the storm's path, and positioning surface ships out at sea.

[12] Then, on October 14, the United States Weather Bureau issued a warning for the Carolinas, with the caveat that the worst of the hurricane was expected to stay offshore.

[6] Toronto Hydro called in standby crews as heavy winds were forecast, although they were almost sent home at one point due to a lull in the storm.

[24] In Haiti, Hazel brought flash floods which destroyed numerous villages, and high winds which caused considerable damage to major cities.

However, since the Carolinas, like the rest of the Southeastern United States, were suffering from a severe drought, the heavy rainfall brought by Hazel was welcome.

Going north, Hazel turned extratropical by midday when it merged with a cold front; however, it retained hurricane-strength winds and it continued to drop heavy rainfall.

[22][37] Effects of the storm was able to break the incomplete battleship USS Kentucky from its moorings when she was based in Philadelphia Naval Shipyard as a parts ship, resulting in her running aground.

[42] Hazel lost a considerable amount of moisture when crossing the Allegheny Mountains, which raised rivers and streams in the Pittsburgh area significantly above the flood mark.

[46][47] Floodwaters slowly rose in the Holland Marsh – a bowl-shaped valley near Bradford – allowing people to escape to the town.

[51] The Etobicoke Creek also overflowed its banks at the village of Long Branch, killing seven people after many dwellings were swept into Lake Ontario.

Pan American World Airways offered the use of its planes to assist with the delivery of aid,[57] and the US aircraft carrier USS Saipan deployed 18 helicopters to help deliver supplies.

On October 17, President Dwight D. Eisenhower declared a "major disaster" in the Carolinas, and offered "immediate and unlimited federal assistance.

[63] The heavily flooded areas were expropriated and barred from having homes, and most of the land was later converted into an extensive park system along Toronto's rivers.