FORT CAMPBELL, Ky. -- A soldier's wife has been charged with setting a fire at their Kentucky Army base home that killed her two young children.

Related: Images | Video: Soldier's Wife Charged In House Fire

Billi Jo Smallwood, 35, also faces a federal charge of attempting to destroy a residential facility for members of the U.S. Army that caused the death of two minors, the U.S. Attorney's Office announced Tuesday.

The May 2007 fire at Fort Campbell killed 9-year-old Sam Fagan and 2-year-old Rebekah Smallwood, and injured her husband, Army Spc. Wayne Smallwood. The Smallwoods' infant daughter, Nevaeh, was not injured.

Billi Smallwood, of Brunswick, Ga., who is in federal custody, could face execution or life in prison if convicted. She does not have an attorney, a spokeswoman for the U.S. Attorney said.

The fire broke out in a two-story housing unit where six families lived in a housing development called Lee Village that dates to the 1940s and was in the process of being torn down. About 10,000 family members live in housing on the sprawling base that straddles the Tennessee-Kentucky state line, according to the most recent Fort Campbell fiscal report.

"Arson cases tend to be very circumstantial. There's not a lot of direct testimony. You have to check facts over and over, and in this case, because of the deaths involved, we wanted to be painstakingly absolutely sure before we went ahead and asked a grand jury for an indictment," said Kevin Kelm, ATF.

The federal grand jury indictment said Smallwood planned to set the fire with the intention of causing a person's death. The U.S. attorney did not say who she was targeting and the full indictment was not yet available.

Cathy Gramling, a spokeswoman for Fort Campbell, said Smallwood's husband is still assigned to the base but had no further comment.

Dawn Masden, a spokeswoman for the U.S. Attorney's Office in Paducah, said Smallwood was scheduled to appear for a hearing Tuesday afternoon, but was unsure if a judge would decide then whether she would remain in custody.

She also has an arraignment scheduled before a U.S. magistrate judge on Dec. 10.