Winner, SD – Four people remain hospitalized after being seriously injured during a house explosion in Winner that authorities believe was due to a faulty propane line.

The blast occurred at about 6:30 a.m. on Friday. Five people were hurt, and four were transported to a Minneapolis burn unit.

The Hennepin County Medical Center reports that one woman and a 7-month-old baby were in critical condition on Monday, while another man was listed in serious condition and a another man was listed as satisfactory. Another woman was released from the hospital Sunday.

Winner police officer April Al-Salihi, who is related to some of the victims, says investigators believe the blast’s cause was linked to a propane line in the upstairs part of the home.