LOCKPORT — Authorities said a woman and her two daughters were stabbed in their apartment, which was then set on fire.

A Lafourche Parish Sheriff’s Office spokesman said investigators have not arrested anyone in the deaths early Sunday of 29-year-old Jacqueline Gautreaux Nieves, 20-month-old Isabella Nieves or 6-year-old Gabriella Nieves.

Deputy Brennan Matherne said Nieves’ husband is being questioned as a person of interest.

He said investigators believe the fire was set, possibly to cover up the stabbings.

Investigators don’t know if more than one attacker was involved.

He said the coroner has sent the bodies to Jefferson Parish for full autopsies Monday. Those will determine whether the three died before the fire.

Matherne said Lockport police told him this is the first homicide there in about 40 years.