A 14-year-old Adelaide boy has been charged with manslaughter after a high-speed crime spree on Sunday, where a 40-year-old woman was killed on her way to work.
The force of the collision rammed the victim's car more than 50 metres down the road and wiped the front of the vehicle clean off. Police said she had "no chance" of survival.
Another boy, aged 13, from the Adelaide suburb of Ingle Farm, was also arrested on Monday morning but has not yet been charged, South Australia police confirmed in a statement on Monday afternoon.
The suspects fled the crash site in a stolen car, an action investigating officers slammed as "totally unbelievable" and "an absolute disgrace".
The victim has been identified by The Adelaide Advertiser as 40-year-old care worker and mother-of-two Lucy Paveley from the north Adelaide suburb of Mawson Lakes. Police believe she was on her way to work when her car was hit at 6:37am, travelling north on North Main Road.
She was killed instantly when a stolen white Mitsubishi Pajero 4WD raced through a red light, smashing into the driver's side of her red Nissan Micra.
"The victim was just driving north, going through a green light, obviously minding her own business and this Pajero has gone blasting through the intersection," Superintendent Anthony Fioravanti told reporters at the crash site on Sunday.
"At the speed at which that car was going, unfortunately she would have had no chance," Fioravanti said.
But instead of stopping at the scene and checking on the crash victim, witnesses told police that two boys fled the scene in another car -- a stolen black Mazda sedan, which had been travelling in convoy with the other vehicle.
The arrests of the two teens follow the earlier arrests of three teenagers, aged 17 and 18, on Sunday who were released late on Sunday night without charge, South Australia police said in a statement.
Authorities say the three young men continued to assist police with inquiries, but are not believed to have been involved in the tragic hit-and-run.
The Pajero had been stolen overnight from the coastal suburb of Grange, and a short time later was allegedly involved in a house break-in at Brahma Lodge, where the black Mazda was also allegedly stolen.
At the time of the crash, police had been monitoring both vehicles but had called off a police chase shortly before 6.30am over safety concerns due to the vehicles' dangerous driving.
The cars had been spotted travelling at speeds of up to 110kmh in suburban Adelaide.
Authorities are calling for anyone who may have dashcam footage or who spotted either the white Pajero or the black getaway car in Adelaide on Sunday morning to come forward.
It is city's third fatal car crash involving stolen vehicles in the last 18 months, according to The Adelaide Advertiser.