It's a situation nobody wants: No-one showing up at a birthday party.

That's a realisation mum Rachelle Briannan had to face, as attendees for her son's birthday dropped out in the hours before the event.

Briannan, from Melbourne, Australia, posted an SOS on the Midnight Mums Facebook group on Sunday, asking how she could possibly make it up to her son Taenon after such a massive setback.

"So I'm sitting in my room quietly crying," Briannan wrote. "12 kids were invited to my sons party today, and an hour before every one of them cancels or just doesn't reply to my messages."

It's the first time Briannan's son, who has just turned four, understood "the whole party with friends thing."

"My heart is literally broken for him!! I'm so hurt and angry. What the hell can I do to make this up to him?" Briannan wrote. "Like I made him this huge superhero cake and there's going to be no one to even sing happy birthday to him."

The callout spurred up to 30 young children to the Eltham McDonald's where the birthday party was held at, according to a post by Midnight Mums. Some kids and their parents travelled from far away, with a local party supply company called Veronica's Pantry donating helium balloons for the occasion, which they confirmed to Mashable Australia.

Even the three members of the local Nillumbik branch of the State Emergency Service (SES) showed up to let the kids who attended the birthday to explore their truck.

"When we were informed about [the birthday] were happy to come down and do it, it's not something we do normally — but we thought it'd be fun to have the kids check out the truck," Glenn O'Donnell, a controller from the Nillumbik SES told Mashable Australia.

Sounds like a great party.

Briannan wrote a thank you message to everyone on Wednesday, which was distributed by the the Midnight Mums Facebook page.

"We are just so overwhelmed with love and support it's incredible. People took time and money from their own lives and invested it into me and my son — Taenon," she wrote.

"I was also so happy to see people forming friendships at his party, not just kids but the parents. Everyone there just got along so well."

In the most dire of circumstances, it's proof that there's plenty of awesome people out there.

UPDATE: May 5, 2016, 11:30 p.m. AEST Added comments from Glenn O'Donnell from the SES.

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