Mother-of-four and former teacher killed herself and her kids in house fire hours after chilling last post

Warning: discusses topics some readers may find distressing.

A mother-of-four - who was previously crowned 'Teacher of the Year' at the school she worked at - was this week found to have killed herself and her four children in a fire.

Bernadine 'Birdie' Pruessner had delivered a 'suspicious' post to social media about living 'each day like it's your last', just one day prior burning her brood - twins Ellie and Ivy, nine, Jackson, five, and Millie, two - to death on the morning of Monday (19 February).

St Louis County Police Department later confirmed that investigating officers - who found a nerve-shattering note written by Bernadine on the scene - have ruled the tragedy as a murder-suicide.

"It is believed that Bernadine intentionally set a mattress on fire as that was the point of origin for the fire," the office announced on Thursday.

"A note was also left stating Bernadine’s intentions to take her life and the lives of her children," they added, without disclosing the contents of the letter.

As mentioned, however, 39-year-old Bernadine had left a chilling post on Facebook about her devotion to her children at around 12.15am - just four hours before the fire in her home broke out.

The Missouri professor - who had been in the midst of a brutal custody battle over her twin daughters - wrote online: "All my kids, peacefully sleeping in my bed…Knowing they are loved so fiercely that I’d do absolutely anything for them.

Cordelle Beache/Fox 2 St Louis

"This is my favorite moment," she added.

And on Sunday, the day before setting her home ablaze, the teacher - who worked at Lewis & Clark Community College and was awarded the Missouri Teacher of the Year Award from the American Board for Certification of Teacher Excellence in 2013 - shared a smiling selfie alongside her four kids.

"Us against the world. I’m so blessed to be their mama," she captioned the heartwarming snap.

"Making today one of those live each day like it’s your last kind of days!"

According to a statement written on GoFundMe by her loved ones, Bernadine had been trapped in an 'awful place' recently, in the midst of an ongoing legal battle with her ex-husband and the father to her twins, David Pruessner, from whom she divorced in 2017.

Court records explain that she'd began making plans to move her children to the St Louis suburb of Creve Coeur - 10 miles away - when David filed to block them.

Fox 2 St Louis

Despite the move bringing them closer to him, he'd reportedly refuted her case being that she'd actually be within a closer proximity to her own, somewhat estranged mother, who David described in court as 'psychotic'.

She'd also become embroiled in a legal altercation with the father of her two youngest children, Jared Spader, who was also seeking custody.

Bernadine's lawyer Nathan Cohen later told the New York post: "[David and Jared] coordinated their efforts. She saw her children being used by their fathers as foils and she viewed the process and system for resolution of that those claims as cumbersome, tedious and never ending.

"Each day that Birdie would score a step forward, her ex-husband and or her former boyfriend would undertake an action to denigrate or undermine her role as a mother."

Following the death of his son and daughter, and friend of David's, Jared released a statement: "As dads, right now we have to focus on honoring the four beautiful lives, and we plan to do that together."