Hours after yesterday's funerals of two 18-year-old cousins who died after overdosing on laughing gas, dozens of their fellow high school seniors gathered at the Be'er Tuvia regional high school to mourn their friends. The cousins died over the weekend.

"We just don't understand how something like this could happen to people in our class," one of their classmates said as they sat at the entrance to the school library before meeting with the principal, psychologists and the head of the regional council to discuss the incident.

"They're just now starting to digest the tragedy," one of the teachers said.

Omer Tzur and Avishai Klomeks were found dead early Saturday near the southern moshav of Orot, next to a tank of nitrous oxide. The teens had been at a party with laughing gas and then wanted to keep partying on their own.

Police arrested two combat soldiers on Saturday afternoon on suspicion of stealing the laughing gas tank from a dental clinic.

One teen sitting on his own yesterday in a corner of the school campus had been at the party. He said lots of people were lining up to inhale the gas.

"We were sure it wasn't dangerous," he said. "How could we have lost friends because of something so stupid?"

"We should have said something," he said. "Maybe it would have been possible to prevent this death, if one of our friends would have said, 'Enough. This is something we don't touch.'"

Another classmate said the students "only now understand the severity" of inhaling laughing gas.

"Our friends were good kids. But we should have stopped them," he said.

Some of the students burst into tears as regional council head Ze'ev Shor implored them to keep away from substance abuse.

"You don't need artificial means to be happy and to succeed in life," he told them. "Running away from reality will take you to the abyss, and there are some who fall into the abyss because of it. I'm asking you not to do yourselves irreversible damage."