Driver detained after fatal hit-and-run collision on S8 expressway in Prosienica

Collision on the S8 expressway

Around 6:00 AM on Sunday, 20 September 2026, a fatal two-car collision occurred on the 558th kilometre of the S8 expressway in Prosienica, located between the Podborze and Prosienica junctions. The crash involved a Mercedes driven by a 39-year-old man and a Seat occupied by two men aged 30 and 31, all residents of Podlaskie Voivodeship. Initial police findings indicate that the Mercedes struck the rear of the Seat while travelling on the carriageway heading towards Białystok. The force of the impact crushed the rear section of the Seat. Responding officers discovered the wreckage along with both occupants of the Seat lying outside the vehicle.

Casualties and emergency response

Emergency medical personnel immediately began cardiopulmonary resuscitation on the 30-year-old passenger, but he died at the scene from his injuries. The 31-year-old occupant remained conscious despite sustaining injuries and was transported to a local hospital for medical evaluation. Police spokeswoman Marzena Laczkowska described the immediate intervention at the scene.

Resuscitation of the 30-year-old began immediately. Unfortunately, despite the quick response, his life could not be saved. Meanwhile, the 31-year-old, conscious despite his injuries, was taken to the hospital.

Officers secured the deceased victim's body for a forensic autopsy to establish the exact cause of death. Medical personnel also drew blood samples from the 31-year-old as part of standard investigative procedures.

Flight and capture of the suspect

Following the crash, the 39-year-old Mercedes driver failed to stop and provide assistance to the injured men. The driver drove away from the site before abandoning the Mercedes further down the road to continue his escape on foot. Officers from the traffic division of the District Police Headquarters in Ostrów Mazowiecka tracked down and detained the suspect shortly thereafter. Sobriety tests confirmed that the driver was sober when apprehended.

The man was placed in a police cell, where he will await the actions and decisions of the prosecutor. He will probably face charges on Monday. The man was sober at the time of detention.

The suspect remains in police custody while awaiting formal charging decisions from the prosecutor's office.

Traffic disruption and ongoing investigation

The collision caused extensive road blockages on the S8 expressway in the direction of Białystok. Emergency crews, including firefighters and police operating under prosecutorial oversight, diverted traffic through the S61 expressway interchange toward Łomża, Suwałki, and Ostrołęka. Road authorities cleared the wreckage and restored normal traffic flow by 11:33 AM on Sunday. Investigators are examining the mechanical condition of both vehicles, confirming who was driving the Seat, and determining why the Mercedes motorist fled.