Kym Page had gone to work as a grounds keeper at Haileybury College on Valentine's Day in 2018.

He had sent messages to his wife Catherine Agrotis throughout the day and usually called at 3.15pm to see if she had gone to pick up their son from daycare.

When the phone rang that day it was not Mr Page but the principal of Haileybury urging Ms Agrotis to get to the school immediately.

Seeing so many emergency vehicles at the Berwick school when she arrived, Ms Agrotis knew something terrible had happened.

A large manna gum branch fell in strong winds overnight. Earlier in the day Mr Page discussed the branch with colleagues including the Berwick campus' grounds manager Dale Goodman who had instructed the workers not to touch it.

Mr Page's body was found next to the large eucalyptus branch, alongside a section of branch wood and two chainsaws, one still running.

The 38-year-old was not wearing a safety helmet when he suffered a fatal head injury.

Haileybury has pleaded guilty to two charges - failing to provide or maintain safe work systems and failing to provide information, instructions and training as necessary to enable employees to work safely.

Each carries a penalty of a $1.4 million fine.

Ms Agrotis told a pre-sentence hearing in Victoria's County Court that their two young children had kept her going.

After initially extending her maternity leave, Ms Agrotis left the teaching job she loved at a nearby school because she was unable to drive past the place Mr Page's car should have been parked.

She left their family home, knowing she'd never see her husband's car pull into the driveway or watch their children greet him after work again.

There have also been financial impacts, but Ms Agrotis said they weren't a burden. She called it an honour to give Mr Page the send-off he deserved.

But she said choosing his casket while breastfeeding their daughter was a moment she would never forget.

Ms Agrotis said Haileybury had offered to pay for many expenses that followed Mr Page's death. She received his salary and benefits for three years.

Haileybury also offered full tuition for the couple's two children - something Ms Agrotis said initially left her "ridiculously overcome with sadness".

She knew the offer would never had been made if he hadn't died and accepting the offer was at odds with her pride as a mother.

"I wanted initially to refuse, but then I saw it differently, I saw it as a gift from their dad," she said.

Judge Frank Gucciardo will hand down his sentence at a later date.

Australian Associated Press