British Columbia's Supreme Court heard agonizing details Tuesday of a car crash which killed a young B.C. couple on their way home from a Justin Bieber concert three years ago.

Johnny deOliveira, 21, and Beckie Dyer, 19, were only two blocks from their Maple Ridge home when a Toyota driven by Andelina Hecimovic, 23, skidded, flipped over and slammed into their Suzuki Swift in Pitt Meadows.

The couple died instantly and Hecimovic, now 26, is facing two counts of dangerous driving causing death. Crash investigators allege she was driving aggressively on the night of the crash.

On Tuesday, witness Duncan Buss told court he saw a car speed past him in a right-turn-only lane and through a red light. 

The car swerved to miss a concrete abuttment before the driver lost control. The car flipped over the centre median and tore the roof off the couple's vehicle, Buss said.

Buss said he then ran to the crash scene and looked in the first car. He checked both deOliveira and Dyer for a pulse and movement. There wasn't any.

Then he went to the second car and that's where, he said, he found the driver, a female, hysterical and screaming but seemingly uninjured.

The trial before a judge began Monday and is scheduled to run until Sept. 18.