Authorities say two of the three people killed when a pickup truck crashed into an Iowa Wal-Mart store were employees, while the third was shopping.

Law enforcement officials said Friday that those killed in the Thursday morning crash were 31-year-old Carrie Zugg, of Leighton, and 29-year-old Lindsey Rietveld, of Bussey, both employees of the Pella store, and 76-year-old Ruth Jean DeJong, of Pella, a shopper. DeJong’s husband, 77-year-old Robert DeJong, was injured in the crash and remained hospitalized.

The only other injured person was the driver of the truck, 66-year-old Dennis Mockenhaupt, of Knoxville, Iowa. Investigators say Mockenhaupt plowed at a high rate of speed through a glass front entrance. Officials declined to say Friday what caused the crash, but had earlier said it was believed to be an accident.