Police in Miami-Dade County successfully removed two vehicles with three bodies inside from the rubble of Thursday's pedestrian bridge collapse near the campus of Florida International University, according to Miami-Dade police Director Juan Perez. Four vehicles remain stuck in the rubble. Police believe six people have died from the collapse - including the three whose bodies were recovered Saturday morning. That leaves at least two people who may still be buried in the rubble. Police warned that the final death toll won't be known until all the vehicles have been removed, according to CNN. The latest disturbing news from the accident comes after it was reported Friday that an engineer for the company that designed the bridge called a Florida Department of Transportation employee to warn about "some cracking" visible on the underside of the bridge. However, the state employee was out on assignment that day, and the call - from W. Denney Pate of FIGG Bridge Engineers - went unanswered until Friday, the day AFTER the deadly collapse, per the Wall Street Journal. To be sure, the engineer who reported the cracking noted that, while the damage should be repaired, it didn't appear urgent. "We've taken a look at it and, uh, obviously some repairs or whatever will have to be done," Pate said. "But from a safety perspective, we don't see that there's any issue there so we're not concerned about it from that perspective, although obviously the cracking is not good and something's going to have to be, ya know, done to repair that." The Florida DOT issued a statement claiming that any safety issues with the project were the responsibility of the bridge's design team. "The responsibility to identify and address life-safety issues and properly communicate them is the sole responsibility of the FIU design build team," Florida Department of Transportation said in a statement, adding that at no point was the department alerted to any life-safety issues. The $14.2 million bridge suddenly collapsed Thursday afternoon, crushing eight cars under more than 900 tons of concrete. Its main 174-foot span had been lifted into place on March 10 in a matter of hours, after being built alongside the thoroughfare over the course of months. However, conflicting accounts have emerged regarding what was happening with the bridge at the time of its collapse. Lawmakers have provided differing accounts of what was happening on the bridge when it collapsed. U.S. Sen. Marco Rubio (R., Fla.) wrote on Twitter that the engineering firm building the bridge at Florida International University ordered on Thursday that the cables be tightened. “They were being tightened when it collapsed,” he wrote late Thursday. Other elected officials, including the Miami-Dade County mayor, said they had been informed that a stress test was being conducted at the time of the collapse. University officials didn’t respond to a request to comment. It wasn’t clear why officials allowed the road underneath the bridge to remain open during the time of the work, or why this work wasn’t scheduled for night hours, when there is little traffic. "If it’s a critical stage in the construction, why would you keep traffic going under the bridge during that particular step?" said Ted Krauthammer, a University of Florida civil engineering professor who said he didn’t have direct knowledge of the incident. The Florida DOT said it never received any requests to close the road, nor was it informed of any stress testing. At least two federal agencies, local police and state attorneys are investigating the incident. A team from the National Transportation Safety Board should be on the scene for about a week. Police expect more bodies to be recovered, and have said the death toll could rise. * * * Meanwhile, in a separate report, CNN revealed that one of the company's involved in building the bridge had a history of safety complaints. Munilla Construction Management, or MCM, has done a lot of work for the government, and some of its projects have come under scrutiny. At least one MCM project led to a lawsuit over safety, with records showing OSHA citing MCM for 11 violations involving construction projects in Miami and Hialeah, Florida, between 2014 and 2017. The OSHA violations, which resulted in more than $50,000 in penalties, included citations for employees not receiving proper hazardous-chemicals training before handling concrete, not removing water from excavations and not wearing safety glasses and protective gloves, documents show.