A 27-year-old woman, who lived in the Wilmington rowhouse  where two firefighters were killed and four others injured battling a blaze early Saturday, was arrested and charged Thursday with murder and arson, authorities said.

Beatriz Fana-Ruiz is the daughter of the owner of the house and the stepdaughter of the man's wife, Assistant State Fire Marshal Michael Chionchio said.

She was charged with two counts of first-degree murder, first-degree arson, assault charges and seven counts of reckless endangerment, he said.

The blaze broke out at about 2:54 a.m. Saturday at the two-story brick rowhouse on the 1900 block of Lakeview Road.

Chionchio said Fana-Ruiz was arrested early Thursday without incident by the State Fire Marshal's Office and the Wilmington Police Department. She is in custody.

According to court documents obtained by the Wilmington News Journal and posted on its website, Fana-Ruiz told agents with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives in an interview Wednesday that she had been angry and had gone into the basement of the house, started a fire, then fled from the basement.

Investigators with the ATF and the Delaware State Fire Marshal's Office determined Fana-Ruiz intentionally set the fire by igniting flammable or combustible material with an open flame, causing about $200,000 in damages to the home, court documents said.

Seven people were in the house at the time. Chionchio declined to specify who was in the house at the time.

Lt. Christopher Leach, 41, a 14-year veteran of the Wilmington Fire Department, and Senior Firefighter Jerry Fickes, 51, a 13-year veteran of the department, died Saturday morning after the first floor of the house, which was heavily engulfed in smoke and flames, collapsed. They and another firefighter became trapped in the basement, court documents said.

Missy Napier, who lived in the house with her five children, ages 10 to 17, told the News Journal on the day of the blaze that she, her children and another child were sleeping and awoke to find smoke: "When it started, we started hollering, 'Get out of the house, get out of the house!' " After her children were rousted from sleep, they managed to escape out the back of the house.

The News Journal identified Fana-Ruiz as Napier's stepdaughter.

Two other firefighters, Ardythe Hope and Brad Speakman, remain hospitalized at Crozer-Chester Medical Center in Upland, Pa. Hope remains in critical condition while Speakman is in critical, but stable condition, a hospital spokeswoman said Thursday.

Two other firefighters who suffered burns on their arms were treated and released Saturday from Christiana Hospital in Newark, Del. 

Leach and Fickes were the first Wilmington firefighters to die on duty in 18 years. Services for them begin Thursday.

A public viewing for Fickes will take place at Grace Lutheran Church, 2033 Graves Road in Hockessin, Del., from 5 to 8 p.m. Thursday. A second viewing followed by a Mass – for family, friends and Wilmington Fire Department members only – will take place Friday. The viewing will be from 2 to 4 p.m. and the Mass is to start at 4 p.m.

Leach's funeral will take place at St. Elizabeth Church at 809 Broom Street in Wilmington on Friday. A viewing is scheduled for 10 a.m., followed by a noon Mass. The viewing and Mass are open to family and friends, the Wilmington Fire Department and local first responders.

A public memorial service for Leach and Fickes is scheduled for 1 p.m. Saturday at the Chase Center on the Riverfront, 815 Justison Street in Wilmington. Doors open at noon.

GoFundMe page has been set up to raise money for Leach's and Fickes' families.