The Kansas Department Wildlife, Parks and Tourism officials closed the Flint Hills Nature Trail bridge located west of Ottawa, near the Second Street dam, after Wednesday afternoon’s fire, Tim Matthias, Ottawa fire chief, said.

Matthias said the bridge will be closed for an unspecific time frame until the bridge can be inspected and repaired. Matthias said no damage estimate was available and expects the bridge can be repaired.

The chief said the cause of the fire is still unknown as of early Thursday afternoon. The fire was reported at 4:10 p.m. Wednesday as a grass fire, but firefighters quickly realized the fire as on the bridge.

Matthias said the flames burned into the bridge’s easternmost wooden support beams. The wood was likely treated with a creosote-based preservative, he said, causing the large black clouds of smoke visible from Ottawa Wednesday afternoon. The fire was reported under control at 4:55 p.m., and extinguished at 5:25 p.m.