Winds of up to 230 kilometres (143 miles) per hour battered the territory of 900,000 people and the storm earlier forced the closure of the main airport on nearby Mauritius.

"Three victims," the prefect of La Reunion said on X.

One woman in her 50s was swept away in torrential water in Saint-Denis, while a man was killed in an electrical fire, also in the capital, authorities said.

One other woman died in a mudslide in Trois Bassins, in the west of the island, the prefecture told AFP.

Five more people were injured.

The red alert ordering the confinement of the population will be maintained until Saturday morning, Prefect Patrice Latron told reporters.

More than 180,000 households were without power, more than 170,000 without water while 134,000 people had lost mobile phone coverage, according to authorities.

Residents posted pictures online of uprooted trees, torn-off roofs and flooded homes. Entire streets were inundated and cars washed away.

"I watched my car being overturned by the torrent, and there was nothing I could do," said Adrien, a resident of Saint-Andre on the northeastern coast, who declined to give his last name.

- 'First time I've been afraid' -

Authorities imposed a maximum alert for several hours Friday, confining the entire population -- including law enforcement and emergency services -- to homes and offices.

That was eased so that police and emergency services could circulate but authorities still ordered the rest of the population to remain indoors.

Prefect Latron said that Garance was fiercer than cyclone Belal that killed four people on La Reunion in January 2024.

Garance landed on the island's north and barrelled south before heading back out to sea.

While the violent gusts and torrential rain eased, heavy rain and strong winds persisted.

Residents said the force of the cyclone was frightening.

"This is the first time I've seen a cyclone this powerful, and also the first time I've been afraid," said Vincent Clain, 45, who lives in Sainte-Marie on the northern coast.

He told AFP by telephone that the storm had uprooted trees in his garden. "I thought they would crash onto the house," he said.

Clain, his wife, their son and dog hid in their kitchen, "the safest area of the house".

Aline Etheve, a resident of Sainte-Suzanne on the coast, said she was worried the roof of her house would collapse after the storm destroyed her garden fence.

"I must admit I'm a little scared," she said, adding that her power and wifi access were gone.

More than 800 people took shelter in emergency structures across the island.

- 'Rare intensity' -

Around 100 troops and firefighters were to be dispatched from Mayotte -- a French territory nearly 1,500 kilometres away -- as soon as weather conditions permit. Another 100 are to arrive from mainland France.

La Reunion and Mauritius -- around 225 kilometres to the northeast -- had been on high alert since Wednesday.

Mauritius shut its main airport on Wednesday, while La Reunion did the same on Thursday.

France's Interior Minister Bruno Retailleau said Friday that Garance was of a "rare intensity", while Defence Minister Sebastien Lecornu said armed forces stood ready to provide assistance.

In Saint-Denis, residents had scrambled to stock up on essentials.

Farmers dismantled greenhouses and fishermen pulled boats onto land. "It is a feeling of being powerless," said Jean-Christophe Hoareau, a farmer.

Marie Rose Gaze, 61, who lives in Saint-Denis, told AFP that she had seen "all kinds of things" blown out of a building across from her home. "Satellite dishes, clothes lines and even chunks of cement."

At one point she feared "the whole building would come down", she said.

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