HINTON, Iowa (AP) – Central Valley Ag says two of its workers injured in a northwest Iowa grain elevator explosion this week are now in stable condition. The Sioux City Journal reports that the company released the information on Friday. The explosion occurred just after 1 p.m. Thursday at Central Valley Ag in Hinton. The two injured workers were taken to a Sioux City hospital in serious condition, and then transferred to a hospital in Omaha, Nebraska.

The cause of the explosion hasn’t been determined, but engineering and insurance experts, as well as the Iowa State Fire Marshall, were on site the Friday to try to determine the cause.