Police in Surrey, B.C., say charges have been approved against a suspected impaired driver involved in a fatal crash in May 2011.

Natasha Leigh Warren, 34, of Surrey, has been charged with dangerous driving causing death, impaired driving causing death, causing an accident resulting in death and failure to stop at an accident causing bodily harm.

"This has been a very complex and labour-intensive investigation," said Surrey RCMP Sgt. Drew Grainger.

"Our investigators are pleased that their dedication and hard work has come to the fruition of charge approval and continue to be in dialogue with Crown Counsel as this case moves forward through the court process."

Kassandra Kaulius, 22, died following a crash at a Surrey intersection on May 3, 2011. The popular local softball coach was studying to be a teacher and engaged to be married at the time of the crash.

At the time, police alleged Kaulius was hit by an impaired driver who ran a red light and plowed into her car.

Court documents obtained by CBC News indicate the suspected driver had a blood alcohol reading of .16 — twice the legal limit — two hours after the collision.

Kaulius's parents have called for tougher drinking and driving laws following the crash.