A rendering of what the bridge will look like upon completion
Florida International University News Bureau
BH Photo #419445
Dashcam of collapse
The bridge was under construction, with the south span over US 41 having been prefabricated offsite via "Accelerated Bridge Construction" techniques, and was then moved into place as a whole unit on Saturday March 10, 2018. The north span over Tamiami Canal had not yet been built.
On March 13, an engineer noticed cracks, and at 9:30 AM EDT on March 15 "cracking whip" noises were heard from it. At 1:30 PM, while post-tensioning rods were being tightened, it suddenly collapsed onto cars below on US 41 that were stopped at a red light. Several videos exist of the actual collapse. There were 6 fatalities, including 1 construction worker, and 9 injuries. Multiple investigations are ongoing, including the NTSB, and lawsuits have been filed.
For more information, see national news media, and the wikipedia link below.