As part of its continuing investigation into the collapse of an interstate highway bridge in Washington State last year, the National Transportation Safety Board opened the public accident docket on Wednesday, releasing over 2,000 pages of documents.

On May 23, 2013, at about 7:05 p.m., Pacific time, the Interstate 5 bridge across the Skagit River near Mt. Vernon, Washington, collapsed after the support structures were struck by an oversized combination tractor-trailer traveling in the southbound lanes, according to NTSB. A sedan and a pickup truck towing a travel-trailer fell into the river; two other vehicles were damaged as a result of the collapse. None of the eight vehicle occupants involved in the collapse were seriously injured and there were no fatalities. The bridge has since been repaired.

Investigators are looking into cell phone use by the driver of the pilot car ahead of the truck and the possibility she didn’t radio the trucker warning about the bridge’s height, according to Bloomberg. There is no indication the truck driver violated hours of service or other safety regulations.

NTSB says the documents being released are factual in nature and do not provide any analysis or conclusions as to the cause of the crash. They include reports, interview transcripts, photographs, diagrams and other documents from the investigation. All of these materials are on the NTSB website. Additional material will be added to the docket as it becomes available.

Analysis of the accident, along with conclusions and a determination of probable cause, will come when the final report on the investigation is completed this summer.