Emily Robison, the only member of the popular country-music trio aboard the bus, was not injured.

According to the accident report, the bus pulled over on an overpass in northwest San Antonio at 3:30 a.m. after being struck with an unknown object. Police say the parked bus was partially blocking a westbound traffic lane.

As driver Ross Ellis looked for damage, a pickup truck driven by Larry Cox of Corpus Christi struck the back of the bus. Police said Cox was taken to a hospital for treatment of a cut on his right arm.

Cox told police he took his eyes off the road briefly to answer his cell phone as he was approaching the parked bus, and didn’t see the other vehicle in time.

Ellis had activated the emergency flashers on the bus, but still was partly to blame because the bus was parked in the roadway, the investigating officer wrote in the report.

The Dixie Chicks played a concert in Houston on Wednesday, a night after performing in San Antonio. Their next date on the Top of the World Tour is Friday in Little Rock, Ark.