Fire in a north side duplex Monday night caused extensive damage and sent four occupants to the hospital. Firefighting crews were dispatched shortly after 10 p.m. Friday to the 4100 block of East Haverill Street.

Inspector Jason Ziph with the St Joseph Fire Department tells us the cause of the fire remains under investigation.

Inspector Ziph says the structure sustained an estimated $10,000 damage, and there was another $7,000 damage to its contents.

Ziph says four people were taken to the hospital for treatment of smoke inhalation. One of the victims suffered a burn to the hand. The injury was not believed to be serious or life-threatening.  Ziph says he believes all four were released Monday night.