Stack said staff were sent down almost immediately to check on the students.
Staff and the school counsellor were meeting on Wednesday to ensure they had identified all the students who were there, and to get a sense of what support they needed.
The students were okay and not visibly upset, but they might need further support in time, he said.
“As one boy said to me, ‘I wish I had not seen that’.”
Hutt Valley train services were still disrupted on Wednesday morning.
The police left the scene late on Tuesday night, and Metlink said delays spilled into Wednesday morning due to problems with train repositioning.
“The incident last night limited train repositioning, meaning trains wouldn’t be in the correct place to resume normal services this morning.”
Metlink said the disruption to services between Wellington and Wairarapa on Wednesday were because the trains weren’t able to return to the correct place last night.
Hutt Valley line services, which had also been affected, now appear to be running on schedule.
Buses also replaced trains for some Wairarapa line services, or were operating with reduced capacity.
Hutt Valley line services would be running as normal on Wednesday afternoon.
– RNZ