The Deceuninck–Quick-Step rider careered into the barriers as he jostled for position with Dylan Groenewegen (Team Jumbo–Visma) at the culmination of the 195.8km course from Stadion Slaski to Spodek Katowice.
Eurosport Poland report that Jakobsen's condition saw him resuscitated multiple times at the finish line and his team would later release a statement confirming that the rider was in a medically-induced coma and his condition was serious but stable.
Dr. Barbara Jerschina, who provided medical assistance in the wake of the crash, told reporters that Jakobsen’s life was in danger.
“Jakobsen has extremely serious injuries and his life is in danger,” she was reported as saying by naszosie.pl. Adding that the rider had lost a lot of blood, “had suffered a very serious cerebral cranial injury and a broken palate” which had impacted his breathing capabilities.
Jakobsen and Groenewegen raced elbow-to-elbow after the Deceuninck–Quick-Step rider came up the inside of his compatriot after a hilly first stage of the Tour of Poland. However, as the pair vied for position, Groenewegen appeared to clip Jakobsen, vaulting the latter into the barriers, causing havoc at the finish line. The 23-year-old Jakobsen violently careered into a race official on or next to the finish line - as well as the barriers - while a host of other riders also crashed as they attempted to avoid the carnage ahead of them.
Four other riders were injured in the crash, added Eurosport Poland, two of which were hospitalised.
The severity of the incident was immediately apparent to Eurosport commentator Rob Hatch who said: “absolutely hellish crash on the finish line".
“Oh dear,” continued Hatch.
That looks awful. Chaos at the finish line. I am afraid I have not seen anything like that for a long, long time.
Groenewegen initially picked up the stage win, but the result paled into insignificance considering the crash that proceeded it, and the stage winner would later be disqualified, and condemned by the UCI, who said in a statement that they "immediately referred the matter to the Disciplinary Commission to request the imposition of sanctions commensurate with the seriousness of the facts".