LYTTON, Iowa (AP) — Three people have been taken to hospitals in serious condition after an explosion at a protein processing plant in northwest Iowa. The Sac County Sheriff’s Office says three people were involved in a welding storage tank when the explosion occurred just before 6 p.m. at the Proliant facility in Lytton.

The Sioux City Journal reports that two people were taken to Loring Hospital in Sac City. A third person was taken to Stewart Memorial Hospital in Lake City and then transferred to an Omaha hospital. Their names have not been released. The State Fire Marshal’s Office and emergency personnel from Lytton, Sac City, Rockwell City and Lake City assisted with the incident.

Lytton is about 83 miles east of Sioux City.