GRAFTON (AP) - Two men accused of binding, beating and sexually assaulting a woman after breaking into her farm home have pleaded guilty.

Byron Thompson, 36, and Jason Waldner, 24, both farm workers from Grafton, face 15-year prison sentences if their plea agreement is approved by Judge Laurie Fontaine.

Fontaine ordered a presentence investigation Thursday. Both men must have a sex offender risk assessment, Walsh County State's Attorney Sharon Martens said.

Authorities said the two men broke into the home of a 43-year-old woman, a farmer who lives alone near her parents' farm, on the night of Aug. 19-20, as she slept. The woman was beaten, sexually assaulted and restrained with belts, authorities said.

The woman later identified Waldner as one of her attackers, and then identified Thompson as someone who had worked for her family.

Fontaine asked both men separately what they had done on the night of Aug. 20, and men replied they had entered the woman's residence through a window. They said they had been drinking and had taken drugs. Waldner specified methamphetamine.

Fontaine asked them why they had chosen the woman's residence, but neither had an answer.

Martens said both men would serve 15 years in prison for gross sexual imposition or being an accomplice to gross sexual imposition, and burglary.

She said the plea agreement is acceptable to the woman who was attacked, who was in court Thursday.

"This case shocked me and shocked the conscience of the community," Martens said. "People are concerned, upset, angry. This could have been any woman. Anyone's mother, sister, daughter, girlfriend, wife."

Thompson and Waldner face the possibility of more severe sentences if the plea agreement falls apart.

Sentencing has been set for July 18.

Gross sexual imposition and accomplice to gross sexual imposition are Class A felonies, punishable by a maximum of 20 years in prison and $10,000 in fines. Burglary is a Class B felony.

If the agreement is accepted, both men would pay about $1,050 in court fines and fees, and they will undergo chemical dependency evaluations. They will each have 255 days credit for time served and charges of felonious restraint and aggravated assault against them will be dropped.

The plea agreement also bars Thompson and Waldner from contact with the woman or her family.

The woman's victim impact statement will be considered before the plea agreement is accepted, Fontaine said.

"Frankly, this is every woman's worst nightmare," Martens said after the hearing. "Fifteen years is an appropriate time for committing an act as these gentlemen have admitted they committed."

Attorneys for the defendants declined comment after the hearing.