LAUREL — Three people were injured in a house fire Tuesday, including one critically and another seriously, the Delaware State Fire Marshal’s office said.

The blaze before 3:30 p.m., occurred in the 100 block of West Second Street, spokesman Michael Chionchio said. The Laurel Fire Department arrived on the scene with smoke and flames engulfing the three-story house, he said.

Firefighters entered the burning home and rescued three occupants.

Mr. Chionchio said a 76-year-old female resident was transported to Nanticoke Hospital in critical condition suffering from smoke inhalation and burns. She was later flown by helicopter to the Crozer-Chester Medical Center in Upland, Pennsylvania.

A 71-year-old female resident was transported in serious condition to Nanticoke Hospital for smoke inhalation.

A 68-year-old female was also treated at Nanticoke for smoke inhalation and burns. She was listed in stable condition Wednesday.

State fire investigators are searching for the fire’s origin and cause, Mr. Chionchio said. The three-story house was heavily damaged by the fire, estimated at $175,000.

The American Red Cross has been requested to provide emergency assistance to the victims. Four residents have been displaced, said Mr. Chionchio. Several cats remain missing from the house.

Smoke alarms inside the house did operate, Mr. Chionchio said, and there were no residential sprinklers.