Meyers faces a maximum penalty of two consecutive life sentences in prison. Prosecutors will seek the maximum penalty, Washington County State's Attorney Charles Strong said after Thursday afternoon's hearing.
On the night he set the fire, Meyers was drunk and stressed out because he was out of work, Cirincion said.
Meyers appeared in court Thursday wearing faded jeans and a brown T-shirt that read, "I'm not lucky. I'm good."
The girls' mother, Melissa Lindeman, was aware of Thursday's hearing but was not in court, Strong said.
The girls' grandmother and an aunt and uncle were in court for the hearing. They wore T-shirts on which were pictures of the girls under the words "Our Angels."
Prosecutors offered the plea deal only after consulting with the girls' family, which agreed to the deal, Strong said.
Lindeman was at home asleep the night of the fire. Meyers told investigators he was able to help her out of the house but couldn't reach the girls, Cirincion said when reading the statement of facts.
After Lindeman got out of the house, she went to get Meyers' stepbrother, Michael Hovermale, who opened his door to find Lindeman naked and bleeding, telling him the house was on fire and her children were trapped inside, Cirincion said.
Hovermale and Meyers climbed the house porch roof trying to get to the girls, but fell off the roof when they were overcome by smoke, Cirincion said.
Investigators interviewed Meyers five times. At first, he said he had been watching a movie in the living room when he heard a noise in the basement. Meyers claimed he went to investigate the noise and saw the exterior basement door was open, and an orange light flickered inside.
He told a similar version of what happened a few days later when investigators interviewed him a second and third time.
During a final interview, at the Maryland State Police barracks in Hagerstown, Meyers gave investigators a statement that was consistent with evidence about the fire's origin and presence of ignitable fluids at the scene, Cirincion said.
Meyers told investigators he poured lighter fluid on the electrical panel breaker box and on a mattress in the basement. Meyers ignited a piece of paper with his cigarette lighter to start the fire, according to the statement of facts.
He regretted starting the fire and tried to put it out with clothes, but was surprised at how quickly the fire spread, Meyers told investigators.
Meyers managed to pull Lindeman out of her bedroom window but was unable to get to the children. He thought he would have had time to get everyone out of the house, Meyers told investigators.
As he pleaded guilty and answered the judge's questions Thursday about whether he understood the proceedings, Meyers repeatedly brushed tears off his cheeks.
Nicole and Mary Gross transferred to Hancock Middle-Senior High School for the 2008-2009 school year from Allegany County Public Schools, where they last attended Braddock Middle School, school officials have said.
"They always had a smile on their faces," Principal Eric Michael said shortly after the fire.
Meyers' attorney, Deputy District Public Defender Eric Reed, declined to answer questions after Thursday's hearing.
Washington County Circuit Judge John H. McDowell ordered a presentence investigation be completed for Meyers. A date for a sentencing hearing will be set once that report is finished.
Meyers was being held Thursday evening at the Washington County Detention Center, a deputy there said.