After slamming eastern Cuba as a bigger, stronger and deadlier storm than expected, Hurricane Sandy on Friday churned toward what could be a wicked visit early next week to the northeastern U.S. from a massive hybrid weather system quickly dubbed “Franken-storm.’’

Sandy was weakening but still expected to generate at least one more day of nasty weather across South Florida, with storms and tropical storm-force gusts brushing the coast Friday — conditions bad enough for many schools in Miami-Dade, Broward and Palm Beach counties to cancel activities. (Friday was already a teacher work-day in Dade and Broward public schools.)

But the state will likely escape mostly unscathed from a hurricane that left a growing death toll and a trail of collapsed buildings and bridges, shredded roofs, ruined crops and flooded hospitals across three Caribbean countries and the Bahamas. The death count leapt to 21 on Thursday — one in Jamaica, 11 in Cuba, and nine in Haiti, which endured another day of nonstop rain, flooding and mudslides.

In Cuba, the dead included a 4-month-old boy and an 84-year-old-man, according to state-run television.

Reading a report from Cuba’s Civil Defense, an announcer on Cuba’s nightly newscast said nine of the deaths were in Santiago province and the other two in Guantánamo. Most of the deaths occurred, according to the newscasts, when homes collapsed.

Bands of rain from Sandy were still affecting central and eastern Cuba Thursday night, causing flooding along the southern coast of Guantánamo province. Cuba’s Institute of Meteorology said flooding was also expected on the north coast from Holguín to Villa Clara. Civil defense Col. Miguel Angel Puig said Sandy’s intense rain could affect 200,000 people in Cuba.

At 8 a.m. Friday, the National Hurricane Center said the storm's sustained winds fell to 80 mph, Category 1 strength, as it passed near Great Abaco Island in the Bahamas. It is moving northwest at 10 mph.

In Cuba, the heaviest damage appeared to be in the Holguín province and the historic city of Santiago de Cuba, close to where Sandy intensified in the hours just before roaring ashore at the Mar Verde beach area as a powerful Category 2 storm with estimated 115 mph winds.

Residents emerged Thursday to survey widespread damage: flattened or partially collapsed homes in some areas, smashed windows in tall buildings, splintered power poles and roads blocked by debris. There were no confirmed reports of deaths.

A damage report broadcast Thursday on Cubavisión, Cubavisión Internacional and Radio Habana Cuba showed Holguín residents wading through waist-deep water trying to salvage items from flooded homes and hundreds of bags of sodden flour inside a Santiago food warehouse that had lost its roof. Television towers and power poles were left splintered.

Ado San, a journalist reporting from Santiago, said, “The panorama here is very difficult, very sad, very hard.’’

José Rubiera, head forecaster at Cuba’s Institute of Meteorology, called the damage “grave,’’ saying that Sandy had defied typical behavior as it crossed Cuba’s mountainous terrain.

“The curious thing is that Sandy scarcely weakened” as it crossed the Sierra Maestra, he said. At La Gran Piedra, a 63,000-ton boulder perched above the Caribbean just east of Santiago, he said wind gusts of up to 152 mph were recorded.