National Transportation Safety Board Chair Jennifer Homendy announced on Friday that the federal agency would be launching an investigation to determine the factors that led to the bridge collapse.
On Sunday morning, an NTSB crash reconstructionist mapped out the scene of the crash using a drone, Homendy said during a press briefing.
"We did an initial inspection of the structure and the legs under the deck of the bridge. We want to see how the structure came to rest and we're looking for things like signs of corrosion, signs of fatigue cracking," Homendy said. "We're also looking to identify areas for closer examination."
The board will also collect and evaluate inspection reports, maintenance records, video footage of the collapse, and witness statements throughout the course of its investigation, Homendy said during the briefing.
"In addition, over the next coming weeks, we are going to put this bridge under a microscope. We're going to look at the entire history of this bridge from the design, construction, maintenance, repair, all work up until the day of the collapse," Homendy said.