Inset: Janieka Ellington being pinned down and held by a U.S. Army soldier in Washington state, according to police (KING/Nathan Wilkinson/YouTube). Background: The aftermath of Janieka Ellington's alleged car crash and stabbing attacks on Interstate 5 in Washington state's Pierce County (KING/YouTube).

A Washington state mother stabbed her 10-year-old daughter inside a mangled SUV after deliberately crashing it, then climbed out and chased her older daughter with the knife until two U.S. Army soldiers intervened and wrestled the weapon away, according to police.

Janieka Ellington, 35, is facing charges of attempted murder and assault for the alleged attacks against her two daughters, ages 15 and 10, on Monday in Pierce County. A probable cause affidavit obtained by Law&Crime details the allegations against her, including what led to the morning crash on Interstate 5 and how two service members intervened.

"Ellington was driving extremely erratic prior to the collision," the affidavit says, citing statements provided by witnesses.

According to Ellington's children, their mom had "woken them up in the middle of the night" and told them both that "people were following them and they needed to leave," the affidavit says.

"During the drive, Janieka … stated she would kill [the children] before the people that were following them did," according to the affidavit. "[One of the children] stated she did not see anyone following them and believed her mom was delusional."

Ellington allegedly crashed her Volkswagen Tiguan into a concrete barrier on the left shoulder of I-5 while traveling in the southbound lane around 9 a.m. Monday. Her children told police that Ellington pulled out a knife and "tried to kill us" while driving to their uncle's house, according to the affidavit.

"[The 10-year-old] said her mom started to say they were all going to die and her mom crashed the car," the affidavit recounts. "As her sister … was getting out of the car, her mom began to chase her with a knife, yelling 'I'm going to kill you!'"

Police say the 10-year-old asked investigators "why was my mom trying to kill us and am I going to die?" Both girls were injured in the crash and stabbing attacks, and both were taken to the hospital.

"It was later determined that after the collision had occurred, Ellington stabbed the younger daughter while she was stuck in the vehicle and then outside the vehicle, Ellington was attempting to stab [the 15-year-old] before the military personnel removed the knife from Ellington," the affidavit says.

Authorities received multiple calls about the crash and arrived on scene to find Army Sgt. Ricardo A. Nunez, a 7th Infantry Division (Multi-domain Command-Pacific) soldier, and Sgt. 1st Class Jeff Hytower, a 68C practical nursing specialist instructor, with Ellington.

Nunez had Ellington "pinned to the ground" while Hytower stood behind them after helping remove the knife, the affidavit says.

"This lady was trying to stab the other girl when I got her," Nunez yelled, according to the affidavit. "We took the knife away from her."

Sgt. Alexis McKay, a Washington National Guard combat medic, also was at the scene and told local ABC affiliate KOMO about what unfolded.

"The sergeant first class that was involved was able to hold the arm in place with the assistance of the 15-year-old daughter, trying to keep it off of her stomach," McKay said. "They were able to disarm her and then pin her to the ground while I pulled the 15-year-old away."

Ellington's older daughter suffered bruises on her right cheek, a fractured tibia, a laceration on her right upper thigh from a stab wound, abrasions on her lower back and right upper back, and cuts on her ankle "from the knife mom had," according to police.

The younger daughter was hospitalized with an injured right ankle, a cut on her left hand, a contusion to the right side of her temple and severe back pain.

Police reported smelling alcohol on Ellington at the scene. She was taken to the hospital, where she allegedly told investigators that she had been "drinking whiskey straight" the night before. Her last drink was sometime between 10 p.m. and midnight, and she "never went to bed," the affidavit says.

"The state is gravely concerned for the safety of the victims as the allegations assert that the defendant attempted to kill her children via stabbing as well as via motor vehicle collision on busy freeway and continued in her quest after the collision failed by chasing one of the victims with a knife," prosecutors said in court documents obtained by Law&Crime. "The state is gravely concerned for the safety of the public given the collision and the multiple lives endangered by what appears to be an intentional and purposeful act and the combination of those acts with alcohol on board."

A judge has ordered Ellington to undergo a mental health evaluation. She is being held without bail and is scheduled to appear in court for a competency hearing on Oct. 20.