Washington, D.C. officials say a truck impact likely caused the June 23 collapse of a pedestrian bridge spanning a six-lane highway in the nation’s capital.

The noontime collision on DC Route 295 appears to have lifted the chain-link enclosed concrete bridge off its moorings, trapping the truck and sending structural debris onto several other vehicles, according to Chris Geldart, acting deputy city mayor for public safety.

Six motorists reportedly suffered non-life-threatening injuries. Nobody was reported to be on the bridge at the time of the impact.

A full incident investigation is underway, Geldart says, adding that while the truck itself would have fit beneath the bridge’s posted clearance of 14 ft, a rear apparatus for lifting canisters may have exceeded that height. Nearby overpasses along the truck’s route were also being checked for evidence of impact.

No structural issues were identified during the bridge’s most recent structural inspection, conducted earlier this year.

Cleanup from the crash is expected to last at least a full day, including debris removal and mitigation of spilled diesel fuel from the truck.

Geldart said a strategy for replacing the bridge will be developed once the condition of moorings and adjacent stairway platforms have been fully assessed.