The then 21-year-old was sitting at her desk at Victoria Police's Russell Street headquarters in Melbourne on March 27, 1986, when a car bomb detonated outside at 1.01pm.
The blast fatally wounded Constable Angela Taylor, who was also 21 at the time and crossing the road to collect lunch for her colleagues after losing a coin toss.
Const Taylor suffered extensive burns and died 24 days later, marking the first time an Australian policewoman had been killed in the line of duty.
Another 21 people were wounded by the bomb and a series of other explosions as the fuel tanks of nearby cars ignited.
Ms Richardson, who was among those injured, was meant to start work at 1pm that day but arrived 20 minutes early, keeping her out of more harm's way.Â
The force of the blast threw her off her chair to the other side of the room.
"My reaction was that I'd been shot," the Police Veterans Victoria chief executive told reporters on Friday.
The young constable continued to work for another eight hours until she was put in a wheelchair and ordered to go home, where she stayed in bed for eight days.
She later learned a piece of chipboard randomly placed against a window shielded her from catastrophic injury.
"It was actually that piece of board that saved my life that day," Ms Richardson said.
Forty years later, Ms Richardson remains "terrified" of thunderstorms and cars backfiring but reckons she has gained a quiet strength and resilience from the traumatic experience.
The Victoria Police Academy in Melbourne's outer east hosted a service on Friday to mark the 40th anniversary of the bombing.
Const Taylor's parents, Marilyn and Arthur, and brother Michael attended, along with past and present chief commissioners and dignitaries.
Const Taylor's mother read a poem titled A Gentle Warrior and remembered her as "everything good in life".
"Angela is with me every day," she said.
Her brother Michael told the assembled crowd his younger sister was his adversary and advocate.
"Her loss has left a void ... but beside that void is a treasure chest filled with wonderful memories and shared experiences," he said.
The Russell Street attack is considered one of Australia's first and most brutal acts of terrorism, with the bomb set to explode when most people would be heading out for lunch.
The blast was so large debris was found three blocks away.
The horrific impact prompted some of those involved to leave the force and left many others struggling with physical and psychological scars.
Victoria Police Chief Commissioner Mike Bush branded the bombing a "despicable act" and one of the force's "darkest days".
He described Const Taylor as an innocent and beautiful young police officer and suggested she had the chops to stand in his shoes before her life was snuffed out.
"She could have, very much, been up here making a similar speech," Mr Bush said.
Const Taylor was the top police graduate of her class and came into the force in an era when just two per cent were women.
The top graduate of every Victoria Police class receives an award named in her honour.
There have been 178 Victoria Police members killed on duty.
Most recently, Senior Constable Vadim de Waart-Hottart, 34, and Detective Leading Senior Constable Neal Thompson, 59, died following a shooting in Victoria's high country in August.
Sen Const de Waart-Hottart's parents Carolina and Alain, who live in Belgium, were at Friday's ceremony.
The service included a minute's silence and a special tribute by the Victoria Police Pipe Band.
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