Lilly's partner died in a freak accident at their engagement party. She's pregnant with their child.

Last weekend, Lilly Watts and her fiancé, Senior Constable Liam Trimmer, were celebrating their love when Liam unexpectedly fell and died in a freak accident at their engagement party.

During the celebration held at their Perth home, Liam fell and cut a carotid artery in his neck, ending his life almost instantly.

The couple had just announced they were expecting their first child. 

Watch: A widow shares her story. Post continues below.

Lilly, a clinic registered nurse at Royal Perth Hospital, is 14 weeks pregnant. She told Mamamia that Liam was "truly so excited to be a Dad".

"I have never known a love like Liam's and this heartbreak and emptiness is just so overwhelming," she said.

"He will always be the love of my life and our baby will know the wonderful man he was."

Liam, who moved from the UK to Australia, had been a police officer for a number of years.

WA Police Commissioner Col Blanch described him as an "extremely well-liked" and respected officer with his "whole life ahead of him".

"I know when my phone rings early in the morning from a senior officer, generally it's not good news, and tragically it wasn't," he said in a statement. 

"I know everyone that was involved is really, really hurting at the moment, and I think they wish they could just wake up from this nightmare."

Police Commissioner Blanch also told The Telegraph that "everything was done to try and save him".

An old friend of Lilly's, Melinda Kelly, says her close friend now finds herself navigating uncharted waters. 

"Not only has she lost her soulmate, but she also carries the precious gift of new life within her. At almost 14 weeks pregnant, Lilly now faces the prospect of raising a child without her beloved partner, while also grappling with the financial responsibilities that come with homeownership," she said.

Mel has also set up a GoFundMe.

"Lilly's resilience and unwavering spirit have always been her defining qualities, and now, more than ever, she needs our love and support," the fellow registered nurse wrote on the fundraiser's page.

"Let us come together as a community to rally around her in this time of need, offering whatever assistance we can to help her navigate the challenging road ahead. 

"Together, we can help light the path forward for Lilly and honour the memory of the man she loved so dearly."

If you would like to contribute to the GoFundMe for Lilly Watts, you can donate here.

Feature Image: Supplied/Facebook.