On the ground lay two prone women, their faces obscured by blood-matted hair, as seen in video of the incident that was obtained by CNN. The roof of the bus they were traveling in was ripped open, and windows were shattered as if a bomb had gone off.
"She's already dead," cried a passerby as a good Samaritan tried to take the pulse of one of the women.
All around the bus lay huge chunks of cement; pieces of a nearby building that had collapsed under the brunt of Hurricane Irma.
Long before Irma, derrumbes -- as Cubans call building collapses -- were a common event. Ornate colonial balconies, facades, sometimes even whole buildings, give way after decades of neglect and come crashing down with little to no warning.
Havana residents joke that their's might be the only city in the world where it's safer to walk in the middle of the road than on the sidewalks, in case the heavy stone edifices come crashing down.
Of the 10 deaths that Cuba has blamed on Hurricane Irma, at least five were the result of building collapses.
Irma hit Cuba as a monster Category 5 storm and laid waste to hundreds of buildings in the storm's path. But Cuban officials worry that many more thousands of structures could be weakened and eventually fall.
According to the state-run newspaper Granma, just in Havana, over 300 miles from the where Irma made landfall, at least 157 homes were destroyed and an additional 4,288 homes were weakened by Irma.
In the weeks to come, the damaged buildings could shift and suddenly disintegrate.
"The combination between the water and the sun create expansion and contraction and that creates structural problems in the building which you cannot predict," said Cuban architect Yoandy Rizo Fiallo. "You don't expect anything and then the building falls."
Cuba has been in an economic crisis since the fall of the Soviet Union and suffered under more than five decades of US economic sanctions. The Cuban government maintains the exclusive right to import items to the island and at state-run hardware stores many building materials are overpriced, shoddy or simply nonexistent.
The lack of new construction has led Cubans to subdivide their homes, putting more strain on already creaking buildings.
Cuban President Raul Castro vowed the country would bounce back from the ravages inflicted by Irma, the strongest hurricane to hit the island in over 80 years.
"One principle remains immovable: the Revolution will leave no one unprotected," Castro said in a statement addressed to the Cuban people. "And measures are already being adopted to ensure that no Cuban family is left to their fate."
But many Cubans are waiting for that help to arrive.
A building collapse in Havana killed two brothers who lived alongside Litza Sierra Peñalver and her family.
Their apartment building in Centro Habana was already at risk of collapse when the roof over the brothers' apartment gave way, killing them instantly, Peñalver said.
Peñalver said she left the building last year, after living there for over 20 years, when her ceiling also came crashing down. Her son, sister and nephews stayed behind in another apartment, she said.
"Don't live here, danger of building collapse," read a sign scrawled on the wall of the second floor where the men died. Residents of the building hang dried marabu grass over entrances to their apartments and nail dead cockroaches to their doors, Santería traditions to ward off misfortune.
"If you live here, you pray a lot," Peñalver said.
Residents showed cellphone video of Cuban civil defense officials carrying the men's bodies out of the building in what appeared to be large black trash bags.
"It's painful because it could have been avoided if the authorities had taken measures," she said.
Now the back half of the building is open to the elements. Water pours in from holes in the roof and the floor on the second story tilts at an angle.
Cuban government officials contacted by CNN about the case of Peñalver's family and the other residents of the building said they had warned them about the approaching storm and that they were trying to get them to leave the building for their own safety, even if that meant going to a shelter while the government tried to find them permanent housing.
"What happens is they don't accept going to a shelter, they want a permanent solution. As everyone knows when a hurricane comes it's devastating and leaves complicated economic situations," said Eider Herrera Morales, a local government official for the neighborhood where Peñalver's family lives.
But Peñalver rejected having her family going to a temporary shelter, saying they would be stranded there for years until housing was provided for them.
"They were elected to help the people, if not them, who?" she said of the local Communist Party officials, who she said had provided them with scant assistance. "We don't have an answer. They just say 'wait.' "
The rest of the building could go at any time,
"We don't go to sleep," Peñalver said. "Because we are afraid we won't wake up."