Between 300 and 400 students and their parents from the school of 2,100 showed up, as did about 100 members of the school staff, according to Mark Klein, superintendent of the Council Rock School District.
Even the mother of Shamus Digney came to the school Monday, dropping off a tray of hoagies for grieving students, said Klein, who swallowed hard and uttered a one-word assessment: "Remarkable." He declined to give her full name.
Klein also preferred not to identify a Council Rock student who was one of three survivors of the crash. That student, who suffered a non-life-threatening injury, was at the school on Monday, as well, eager to be among friends, the superintendent said.
Klein added that he wasn't privy to what students and parents said to the grief counselors.
"We just watched for kids in crisis and put a counselor with them," he said.
As for his overall message to the school, Klein said: "It's one day at a time. We don't have the answers for something as tragic as this. We can't see our way through a week, a month, a year.
"And, in addition, many of these kids will be going to three funerals at the end of this week. We have to adapt to that."
Funeral arrangements were not yet complete, he said, adding that the school will hold a vigil for the three on Tuesday, between 5 and 7 p.m.
Keffer's death was ruled accidental by Wayne County Coroner Edward Howell on Monday, according to an Associated Press report. Keffer, 15, of Holland, died of "multiple traumatic injuries," according to the coroner's report. Officials in Howell's office could not be reached Monday.
Keffer was dead at the scene.
Digney, of Holland, and Lesher, of Churchville, both 15, died Saturday at the Geisinger-Community Medical Center in Scranton, according to Lackawanna County Coroner Timothy Rowland.
Two of the survivors of the rollover accident were from Wayne County. Their conditions could not be determined Monday.
State police in Honesdale received a call Saturday at 11:34 a.m. about the 2001 Chevrolet Suburban that rolled on Goosepond Road, near Wallenpaupack Lake Estates, in Wayne County's Paupack Township, authorities said. The spot is about 70 miles north of Philadelphia.
Klein said he didn't know what brought the six boys together in the SUV.
He noted that the three who died were athletes: Digney played basketball and football; Lesher played soccer and basketball; and Keffer was known as a gifted lacrosse player.
During the grief session at the school, local police chased media members from the front of the school, banishing reporters to a lower parking lot that was about 75 yards from the building, out of sight of anyone entering.
A school security official said that earlier in the afternoon, a parent "went ballistic" over a photographer taking pictures of students consoling one another.
Editors Note: This story was revised to reflect that while the school opened Tuesday for freshman orientation, classes for all students do not start until Wednesday.