IDAHO FALLS, Idaho -

Idaho Transportation Department contractors have repaired a sinkhole discovered on U.S. Highway 26 in downtown Idaho Falls.

The ITD discovered it earlier this month when they investigated a dip in the asphalt. It was on the north side of the highway under the middle of three railroad bridges that go over the road. Spokesperson Bruce King said the hole underneath measured about 17 feet long, 6 feet wide and 2.5 feet deep.

Crews poured 4 yards of cement grout into the hole to repair it Wednesday.

The City of Idaho Falls was using pipe-inspection cameras to inspect storm drains in the area for additional damage.

Engineers are attempting to determine the exact cause of the sinkhole, which was first reported Tuesday evening. Officials are still awaiting the results of a study that was conducted with ground-penetrating radar. King said water can drain through the lava rock below the pavement and leach out soil and rock, which might have caused the problem.

The road was closed to traffic Wednesday and reopened overnight.