Whangārei Boys’ High School had been aware the caving network where a student’s body has been found was prone to flooding and had done a detailed risk assessment plan.

Searchers looking for the missing Year 11 student found a body on Tuesday evening, police said.

The search was expected to conclude around 5pm on Tuesday but specialist equipment that was brought up from Auckland allowed the search to continue for longer.

Fourteen students and two adults were rescued from the cave in heavy rain on Tuesday morning.

The school had completed a risk assessment for the trip that stated the caves were “prone to flooding” in heavy rain.

It said the instructor was to “check weather leading up to trip and check water levels before trip, if there has been rain”.

“Postpone trip if water levels may be too high,” the assessment said.

Northland was under a MetService orange rain warning at the time.

According to its hourly rainfall totals, light rain (0-2mm) had been falling in Whangārei since 2am on Tuesday.

Police said the group called for help at 10.26am.

Between 10 and 11am, MetService recorded 30mm of rainfall.

The assessment listed drowning, hypothermia, getting lost and fatigue as potential risks, however, it said measures would be taken to lessen these risks.

Those included ensuring “that all students are competent swimmers” while “non-swimmers” should be put “near trip leaders”.

Instructors were also “to set an achievable walking/crawling pace for the level of group’s fitness.”

A protocol was detailed for a situation in which the whole group or an individual got lost.

If a group got lost, the assessment advised they “try to establish where you have gone wrong and correct it, follow the stream to the exit”.

If it was an individual, the group should “establish who is lost and when they were last seen”.

“Stay as group and back track to the last point where they were seen. If you are unable to locate the lost person, instructors to take rest of group out of cave and raise the alarm to get assistance from search and rescue,” it said.

The risk assessment stated each student would be “issued with helmets, waterproof lights, caving overalls, and caving gumboots”.

According to the Whangārei Boys’ High School website, another group had been scheduled to do the same cave trip today, and two more were scheduled on Friday and next Monday.

In a statement, school principal Karen Gilbert-Smith said a full and comprehensive investigation into the trip will occur.

But for now, the school community was focusing on supporting one another, she said.