SURFSIDE, Fla. (WTXL) — Following the partial collapse of an oceanfront high-rise condo early Thursday morning in Miami-Dade County, many are wondering how this could have happened and what caused the tragedy.

Miami-Dade Fire Rescue said the incident happened around 1:30 a.m. at the Champlain Towers South condominium building, located at 8777 Collins Ave. in Surfside near Miami Beach.

At least one person is confirmed dead and more than 50 people are unaccounted for as crews continue to canvass the rubble.

WPTV's (WTXL's sister station) morning anchor Mike Trim spoke with Jim Rhinehart, Kast Construction vice president, to discuss some of the possibilities and what investigators will be looking at in the coming days.

Rhinehart said there are multiple variables in South Florida that make it unique for construction, specifically for structures built near the coast.

He hinted at the corrosive and challenging environment along the ocean that seaside structures endure over time.

"Salt and chlorides are super corrosive to steel, which of course in a concrete structure like this is the reinforcing that's all inside the concrete," Rhinehart said. "So, if any of that gets exposed, the steel starts to corrode and it swells and it begins a long, slow path of degradation of the structure."

Broward and Miami-Dade counties' building departments have a 40-year recertification program. The Champlain Towers South building was completed in 1981, so it was due for recertification this year.

During this recertification, Rhinehart said inspectors will analyze the building's foundation, soil that has possibly subsided and the overall condition of the structure.

Rhinehart applauded the 40-year recertification process and said he was not aware of a location that has a more stringent approach for building codes.

"It's difficult to know, impossibly really right now, what would have caused something like this," Rhinehart said.

He said it is also possible that this could be a random event, like a truck hitting a building column that might have caused a progressive collapse of a section of the structure.

Looking at the surveillance video Thursday morning, Rhinehart said it looks like the building started to collapse in the center of the building and moved out, but he didn't see anything that triggered any cause to speculate how it occurred.

Discussing the foundation of a building of this nature, Rhinehart said they are often built on what are called auger cast, friction piles that support high-rises.

He said this method of construction is historically a "very reliable foundation" for structures.

On the topic of sinkholes, Rhinehart said it can't be ruled out as a possible cause for the collapse.

"Essentially a building sitting on concrete blocks, sitting on piles that are driven down or drilled down into the ground ... if the ground that all of that is relying on subsides, then there's nothing underpinning the building," Rhinehart said.

In terms of codes, he said the biggest thing that has changed over the last 40 years has been as a result of Hurricane Andrew devastating southern Miami-Dade County in 1992.

He said those code changes are more related to the building envelope, the separator between the conditioned and unconditioned environment, than the actual structure.

Rhinehart said those South Florida code changes after Andrew pertained to things like how the roof adheres to the building and designs of the windows to withstand high winds.

He didn't believe any of those code changes would have an impact on the collapse of a building like the Surfside condo, which was constructed 11 years before Andrew impacted the area.

"Until we understand really what the cause of this was, it's difficult to try to think about how we turn that into sort of future prevention," Rhinehart said.