It was a Monday like no other at schools around the region, the first day back after the tragedy at Sandy Hook Elementary School changed everything.
"If there was a time when we were comfortable, we now have to be aware," said Jonette Marcus, a director of elementary education and curriculum for the Coatesville Area School District.
"You know there's always the possibility of a tragedy within any school district, and we work very hard to prevent any type of tragedy to our students," said Curtis Griffin, superintendent of the Hatboro-Horsham School District. "When it happens, it hurts."
Collingswood Public Schools superintendent Scott Oswald said: "It appears many of our parents did a nice job this weekend with their children, addressing their concerns and answering their questions without overexposure."
Many school officials began strategizing over the weekend about how to react to Friday's shootings in Newtown, Conn. Before Monday, districts had posted notes on websites or sent e-mails to parents about security measures in place, and offered online resources where they could find tips on how to talk to their children about the shooting.
When the morning bell rang, schools already knew the approach they would take. The Pottstown School District and others had extra school counselors and psychologists available to talk to students and staff.
There were moments of silence in Lower Merion Township's high schools before basketball games and at one of the school's winter chorale concert Sunday. The chorale also dedicated a song to the Sandy Hook victims.
High schools in the Downingtown Area School District on Monday started the day with a moment of silence.
Mount Laurel school spokeswoman Marie Reynolds said students and staff wanted to show support to families of Sandy Hook victims and survivors, but nothing had been formalized.
The guideline for dealing with students generally was the same everywhere: Formal discussions or activities might be OK for older students. With younger children, in general, districts did not discuss Sandy Hook unless those students asked.
"For little kids, they want to know how their day-to-day life is affected," said Cherry Hill school psychologist Terry Molony. "They want to know we're there for them."
That was true in Downingtown, too.
In the seven elementary schools that superintendent Larry Mussoline visited Monday, he heard of only one child in one school who had heard that "someone hurt some students last week in an elementary school." The boy's teacher knew what to say: Yes, it was very sad, and, yes, we are doing everything possible to keep you very safe.
Some unintended deviations yielded unintended consequences.
At Greenfield Elementary in Philadelphia, veteran school psychologist Holly Cohen said she had conversations with a few teachers about how their students were handling the news.
In one instance, a substitute had "really raised kids' anxiety" by bringing up the subject Friday, the day of the shooting. On Monday, the students' regular teacher returned and had to calm down her class.
One student acknowledged that he felt sad.
"He said it was because his lizard died," Cohen said. "That's normal. Kids internalize whatever's going on around them in their environment."
The boy's teacher sat with him and comforted him.
The phone was constantly ringing and e-mail dinging at the National Association of School Psychologists office in Bethesda, Md. The association began sending out information to its members as soon as its officials heard about the shooting.
"The major message we want to send is that - as horrific as this event was - schools are very safe places," said Skippack's Amy Smith, the association's president. "Every day, we send millions of kids to school. We need to help students recognize the difference between what possibly could happen vs. something that is probable to happen."
Still, the Hatboro-Horsham district will have a heavier police and security personnel presence at all schools this week. Parents in many school districts expressed particular concern about schools being more vulnerable this week as visitors go into buildings for Christmas parties and winter concerts.
The answer, officials said, is even greater vigilance.
Many school leaders contacted Monday said they would be reviewing security procedures throughout their districts in the coming weeks and months.
The Pottstown School District's director of community relations, John Armato, figured it was tough Monday to be a teacher.
"I was in an elementary building today as the youngsters were coming in, and I'm looking at first graders and kindergarten students, and I had a very difficult time looking at those sweet young children," he said. "So I'm imagining, if I were the teacher in that class, all day long, that would be very difficult."
Some districts said elementary teachers, many of whom also are parents, needed to express their emotions Monday.
The school psychologists association is grieving the loss of one of its members, Sandy Hook's school psychologist, Mary Sherlach.
Posts on the association's Facebook page revealed the sadness and pride school psychologists nationwide feel.
Wrote one woman: "This is so devastating. These names could have been the names of staff and students at my school Rest in peace sweet children and brave staff members. And Mary Sherlach, I am honored to share the same role as you and will continue your mission every day."