In addition to the history of violations these companies have faced in the past, it will be interesting to find out how many of the workers were legal American citizens, and how many were unskilled and/or undocumented laborers. Stay tuned…

According to Fox News, the two firms responsible for building Florida International University’s “instant bridge,” which suddenly collapsed Thursday and left six people dead, are coming under increased scrutiny as details emerge of past engineering failures and inspection fines — including a recent accusation that one hired “unskilled” and “careless” workers.

The $14.2-million pedestrian bridge was supposed to open next year to help students cross a busy road adjacent to the campus. It was an accelerated, joint construction effort by two Florida companies: MCM Construction, a Miami-based contractor, and Figg Bridge Design, based in Tallahassee, who both have worked on dozens of projects nationwide, ranging from military facilities to schools.

“Innovations take a design firm into an area where they don’t have applicable experience, and then we have another unexpected failure on our hands,” Robert Bea, a professor of engineering and construction management at the University of California, Berkeley, told the Associated Press after reviewing the bridge’s design — and the pile of rubble it was reduced to on Thursday afternoon.

As state and federal investigators worked Friday to determine how and why the five-day-old span failed, one factor may have been the stress test Miami-Dade Mayor Carlos Gimenez said crews were conducting on the span. Two workers were on the 950-ton bridge when it pancaked on top of vehicles waiting at a stoplight.

Renderings of the project before it went up showed a tall, off-center tower with supporting cables attached to the walkway, the Associated Press reported. When the bridge collapsed, the main tower had not yet been installed, and it was unclear what builders were using as temporary supports.

But the collapse is not the first incident involving either company.

The Virginia Department of Labor cited Figg for four violations in 2012 after a 90-ton slab of concrete fell from a bridge it was building near Norfolk, according to the Miami Herald.

Figg was hit with a $28,000 fine and the Department of Labor said the company modified a girder without properly inspecting it or getting written consent from its manufacturer, The Virginian-Pilot reported.

The girder ultimately failed and was responsible for the collapse, which ended up delaying the bridge’s opening for three months and leaving four workers with minor injuries.

Despite this collapse, the company said Thursday that “in our 40-year history, nothing like this has ever happened before.”

MCM Construction, meanwhile, in a lawsuit filed earlier this month, was accused of hiring “incompetent, inexperienced, unskilled or careless employees.”

The company is building an expansion to Fort Lauderdale International Airport and a worker there was injured when a makeshift bridge collapsed under his weight, the lawsuit says, according to the Winston Salem-Journal.