"They showed great maturity, calmness and were thoughtful about their friends and school mates," she said.
While having so many patients in the emergency department is unusual for Thames, responding to emergency situations is not.
"We had an incident management team in place within minutes. Thanks to our friends at St John and the police, we knew what to expect," she said.
Doctors, nurses and health care assistants helped out in the emergency department from 11.30pm when the first of the patients were seen.
"Our kitchen staff put on some soup, rolls and sandwiches for the students and for their parents as they started to arrive," said Mrs Mitchell.
"While it was a hive of activity between midday and 1pm, our staff coped very well."
The Westpac air ambulance was on the scene for an unrelated call out from Thames Hospital to Waikato Hospital, she said.