SINGAPORE - He was a 20-year-old probationary driver then. Less than 10 hours after running a red traffic light and crashing into a pedestrian, he caused a passenger in the van he was driving to be thrown out when he suddenly drove off and made a sharp turn before she could close the sliding door.

The back of 16-year-old Ms Norfatin Diana Norazlan's head hit the ground and she was unresponsive. But afraid that he could lose his licence, Muhammad Nizam Abdul Karim told his friends not to call an ambulance.

Ms Norfatin died shortly after.

Describing his actions as clearly irresponsible and indefensible, District Judge Luke Tan on Wednesday (April 20) sentenced Nizam, now 22, to 13 months in jail. He pleaded guilty to four charges: dangerous driving, negligence not amounting to culpable homicide, drug possession and drug consumption.

He will also be barred from driving for five years after his release.

The court heard that on April 12, 2014, Nizam was fiddling with his in-vehicle Global Positioning System device while driving along Bedok South Avenue 2.

At about 7.50pm, he crashed into 18-year-old Chua Shuen Zhi at the crossing outside Bedok Green Primary School. Mr Chua was flung one lamp post away and lost consciousness. He had to have 10 stitches to his forehead.

The van's front windscreen was badly cracked and Nizam's office required him to return it for repairs.

Instead, he used it for an all-night outing with friends at Changi Beach.At about 5.30am, Ms Norfatin and her younger sister Norfarah Aqasha got into the back of the van at a carpark there.

Ms Norfatin got in last and sat cross-legged near the left sliding door, with her back resting against the front passenger's seat.

As she was pulling the door shut, Nizam shot off abruptly and made a right turn towards the carpark exit. The momentum caused the door to slide wide open, and Ms Norfatin was flung out.

She landed on the ground with a loud thud and her sister shouted for Nizam to stop. Her sister and friends wanted to call for an ambulance, but Nizam berated them.

He carried Ms Norfatin to the back of the van with a male friend, and then drove to another carpark. Nizam then went to the beach to chat with a female friend, while Ms Norfarah stayed with her sister.

By 7.20am, Ms Norfatin was cold and her fingers were turning blue.

Her sister called for an ambulance, while a friend went to seek help at a nearby first aid tent which had been set up for an event. Ms Norfatin was pronounced dead in hospital at 9.25am.

Separately, on Nov 10 last year, Nizam was arrested for the possession and use of methamphetamine.

In passing sentence, Judge Tan, highlighting how Nizam failed to call for an ambulance, said: "I agree with the prosecution that the accused's actions were selfish and clearly made a bad situation even worse."