Students' safety was a concern at Warrnambool schools yesterday with many phones, internet and intranet systems disconnected.
Warrnambool College principal Mary Pendergast said her main concern was dealing with emergency situations without a phone connection.
"For us the issue is if a child is hurt or if a staff member is hurt and how quickly we can respond to their needs in the current environment," Ms Pendergast said.
"It is uncomfortable and I feel that there is an element of risk, even though we can contact emergency services."
She said school staff had ensured there was a strategy in place for critical incidents.
"We've identified people here who have got Optus and Virgin mobiles.
"We've identified where they are in the school and we've made sure that we've got one with the first aid officer, one up at PE which is our furthest point (and) one down at our other furthest point, so that if people do need some support then they're there."
A Department of Education media spokeswoman said Telstra had advised triple-zero calls could still be made to emergency services from most mobile phones in and around Warrnambool.
She said police and security services had carried out patrols of schools and early childhood services in and around Warrnambool as a further safety measure to ensure any incidents were responded to immediately.
The spokeswoman said there would be no school closures.
Ms Pendergast said the school's intranet was down, which meant electronic internal communication was not possible.
She said teaching would not be drastically affected.
However, several lessons would be altered such as students studying web-based iLearn.
"You can adjust in these spaces, but for me as a manager, you do feel a bit vulnerable when these sorts of things happen and it does show the reliance we all have now, that has crept up on us a bit, on technology."
Emmanuel College deputy principal Brian Brown said the consequences for the school were not dramatic.
"We've got school as normal ... it doesn't seem to have impacted too much," Mr Brown said.
"I think it's 112 you can ring (in an emergency), so that shouldn't be too much of an impact.
"We have laptops through the year 9 and 10 areas. Part of that is sort of internet research and things like that so it will impact that, probably not so much the other classes."
He said the school's intranet system was not affected, which meant internal phone calls and emails were up and running.
"Internal is ok, which is probably the main thing," he said.
Warrnambool Primary School advised parents they could keep their children home today if they desired, adding that staff may be unable to contact parents if there was an emergency or incident.