It's also leaving many wondering about other oceanfront high rises.
Experts we spoke with on Friday say it's extremely rare for a collapse like this to happen, especially because buildings near the ocean are typically built to weather coastal storms and other elements.
It may take months to know for sure what caused the building in Surfside, Florida to fall. Experts involved in the aftermath of similar local catastrophes say there are several possibilities that need to be investigated.
"There could've been deterioration in the columns down at ground level where moisture is penetrating the skin of the building. That would be a pretty incredible maintenance failure," said Philadelphia-based attorney Robert Mongeluzzi.
Mongeluzzi was lead counsel after part of a building under demolition collapsed onto a Salvation Army store in Center City Philadelphia back in 2013, and the collapse of a parking garage under construction at the Tropicana in Atlantic City in 2003, which killed four workers.
He says part of the mourning process for victims' families is trying to find out what happened.
"They want some explanation for why their loved ones died and they want to make sure it doesn't happen again," said Mongeluzzi.
After the Tropicana garage collapse, qualification standards for special building inspectors were changed in 2006 at the state level.
Structural engineer Kirk Harman worked on the construction of Ocean Casino Resort in Atlantic City, among other projects. He says while saltwater can be corrosive, standard concrete buildings near the ocean can typically hold up against it.
"We haven't seen any significant damage to concrete buildings of this nature along the coastline. That's assuming they're not in direct contact with the saltwater," he said.
He adds that buildings along the coast have to be constructed to withstand hurricane-force winds. He says while theories are already swirling, the investigation into the Miami-area collapse will be lengthy.
"It's very early in the process and it's going to take some time to investigate this and to figure out what exactly happened," Harman said.