Officials say six people remain hospitalized in West Texas after a freight train hit a float in a veterans’ parade, killing 4 people and injuring 16.

Midland Memorial Hospital spokeswoman Marcy Madrid says four people are in stable condition and one is critical Friday. Madrid says a sixth patient was transferred Thursday to University Medical Center in Lubbock. Madrid had no details on that woman’s condition.

Hospital authorities initially said 17 people required treatment following the Thursday afternoon accident in Midland. Madrid on Friday corrected the figure to 16, saying a person seeking treatment at the hospital who was not in the parade float wreck wrongly was included in the accident total.

Investigators are working to determine the cause of the deadly accident.