Elementary school mourns after mysterious murders of kindergartner, 2nd-grader killed in quadruple slaying

After a kindergartner and second-grader were mysteriously killed in their Massachusetts home along with their mother and younger brother, the slain children's elementary school is working "to reassure the kids that they're safe," the superintendent said.

On Thursday, police were called to a West Brookfield home, where they discovered the bodies of Sara Bermudez, 38, and her children, Madison Bermudez, 8; James Bermudez, 6; and Michael Bermudez, 2, the Worcester County District Attorney's Office said.

Bermudez's husband, Moses Bermudez, was in California on business at the time the bodies were discovered, authorities said. Reached by phone Sunday, Moses Bermudez told ABC News he had no comment.

No arrests have been made.

As authorities investigate the quadruple murders, within the school district "police have been highly visible," said Quaboag Regional School District Superintendent Brett Kustigian.

"We're doing everything possible to reassure the kids that they're safe," he told ABC News today.

At Madison and James' school, West Brookfield Elementary, extra counselors and therapy dogs are on hand to provide support for the young students.

"They're doing as well as can be expected," Kustigian said of the students. "The resilience of the staff and the kids absolutely amazing. We're moving forward as best we can."

Among those lifting the students' spirits is New England Patriots player Nate Solder.

Kustigian said Solder came to visit the school within an hour or two of the request and went to each classroom, chatting "with the kids on their level."

"I can't say enough about him and the Patriots organization. Talk about lifting spirits for kids and staff -- just absolutely amazing," Kustigian said. "I think he said it best when he was here: he said the reason that he came was he wanted people to know that there is still good in the world."

Kustigian said "it's been a rough year for our district," noting that in November three high school students in the district died in a car accident.

Kustigian described this Massachusetts community as "small town USA" and "tight-knit."

"Everybody knows one another here and we're supporting one another. So we're going to get through this and be stronger for it," he added.

While no one has been arrested for the quadruple killings, investigators have zeroed in on one clue: a yellow, plastic fuel can that police say is missing from the home.

Investigators urge anyone who has seen a can that fits the description to call the State Police Dispatch Center at 508-867-1170, the district attorney's office said this weekend.

Anyone in the area with active home or business surveillance cameras or dashboard-mounted cameras are also asked to call the police dispatch center.

ABC News' Bill Hutchinson contributed to this report.