Seven vehicles were caught up in the carnage. Three other patients were taken to hospital for treatment for non-life-threatening injuries.
Police said two people in a black BMW SUV were heading north on Lutwyche Road when they hit a moped and killed the rider, a 32-year-old East Brisbane man.
The BMW then crashed into a Subaru sedan, killing the 23-year-old Acacia Ridge driver, before also colliding with a Jeep, according to police.
The duo in the BMW fled the crash scene on foot and were still on the run on Monday.
In the most recent incident, a 28-year-old Lawnton man died after losing control of his vehicle, hitting several trees before crashing into a large gum tree at Rosemount on the Sunshine Coast.
Emergency services were called to the Bruce Highway near the Nambour-Bli Bli turnoff about 10.40pm on Sunday and declared the driver dead at the scene.
Meanwhile, a passing driver found a car that had crashed into a tree in the South Burnett region about 10am on Sunday.
Emergency services arrived at the scene on Chinchilla Wondai Road at Durong, about 205 kilometres north-west of Toowoomba, but the 37-year-old male driver was already dead.
Half-an-hour earlier, a motorcyclist died when he crashed into a tree at Mount Nebo, north-west of Brisbane, about 9.30am on Sunday.
The male rider, aged in his 20s, died at the scene.
The Forensic Crash Unit was investigating the circumstances of all four crashes.
— with Lydia Lynch and Jocelyn Garcia