By Natasha Brown

SEWELL, N.J. (CBS) — In-person instruction for students at Washington Township High School has been delayed until at least Thursday. And officials are pointing fingers at some high school seniors for the reason why.

School has been in session for two weeks in Washington Township, New Jersey in an all-virtual setting.

Plans to begin hybrid learning began on Monday with students returning for in-person classes, but those attending Washington Township High School will have to wait a bit longer.

“Last week we learned of a handful of cases involving students at the high school that had recently tested positive which had some impact on our athletic programming at that time,” said Washington Township Public Schools Superintendent Joseph Bollendorf.

District officials knew of those positive cases but on Friday, a social gathering hosted by some parents for seniors off school property raised some concerns.

“Evidently things were put in place to try to screen students prior to coming in,” said Bollendorf. “But what the folks who organized the event clearly could not know would be the identity of some of these folks who had tested positive.”

School officials immediately contacted the county health department and plans for a return to in-person learning at the high school were halted.

A letter was sent to parents explaining the abrupt decision.

“If we had opened our doors at our schools and allowed these students to come to school not knowing that some of them could have been exposed that could have caused a bigger concern and an outbreak,” said Bollendorf.

School and health officials are still in the midst of investigating and contact tracing. So far, they say results seem promising, unapologetic about erring on the side of caution.

“We want to desperately open our schools, that’s why we’re doing this. We’re excited about our kids coming back,” Bollendorf said.

Superintendent Bollendorf also tells Eyewitness News that so far, there has been no evidence of any kind of an outbreak or some community spread because of that gathering.

Meantime, he says by Tuesday, he will be making his final decision on whether in-person classes will resume here at Washington Township High School on Thursday.