Yrsa Christoffersen was supposed to be enjoying a holiday with her grandchild.

Instead, the 73-year-old was having an autopsy conducted after Andrew Julian Stewart-Smith collided with her car at high speed using a stolen vehicle and then fled the scene.

The tragic consequences were revealed before Stewart-Smith, 29, received his sentence in Brisbane Supreme Court on Monday for his “reprehensible” conduct.

Emotional victim impact statements in a courtroom filled with family members outlined the repercussions following Stewart-Smith’s collision with the grandmother’s car in September 2023.

Yrsa was driving her daughter Maria Christoffersen to work when a Holden Commodore collided with her Suzuki Swift about 6.40am.

She died in the crash and her daughter suffered serious injuries.

“I woke up in a hospital bed, feeling pain like I had never known,” Maria said in her victim impact statement.

“I remember asking where my mum was and they wouldn’t tell me.

“The way they looked at me though, I knew. I could see it on their faces.”

Stewart-Smith had been driving up to 114km/h in a 60km/h zone in a Holden with stolen registration plates when he hit the Christoffersens’ vehicle, sending it airborne.

He fled the scene telling onlookers: “You don’t understand, it’s not my car”.

Stewart-Smith was later located by a police tracker dog in a storm drain, attempting to conceal himself by covering his body in mud.

Yrsa’s family was devastated, with a grandchild set to spend the week with her.

“Instead my mum got to spend the week in the morgue and get an autopsy and my sister Maria got to lie damaged in a hospital bed,” daughter Lorna Christoffersen said in her victim impact statement.

Maria suffered jaw, rib, pelvic and spine fractures along with spleen and liver lacerations.

She lost up to 15 kilograms, was unable to chew food for months and had to blow into balloons to prevent her lungs collapsing.

Stewart-Smith had 35 prior speeding offences since 2013.

Defence counsel Angus Edwards said his client was ashamed of his actions.

Stewart-Smith had pleaded guilty to vehicle theft, dangerous operation of a motor vehicle causing death and grievous bodily harm whilst excessively speeding.

He also pleaded guilty to drug possession and child exploitation material offences.

Police had located methamphetamine during subsequent searches along with 335 images of child exploitation material on his phone.

Justice Tom Sullivan sentenced Stewart-Smith to eight-and-a-half years in jail.