The tunnel in the movie, "Storfjelltunnelen", was 9 km in length. The actual tunnel used in the scenes where the fire department enters the tunnel is Ospelitunnelen (2549 meters).
Includes a prologue where someone walks in a tunnel and then text appears. It states: " Det er over 1100 tunneler i Norge. De fleste av dem er uten nødutganger eller nødrom. Tunnelsikkerheten i Norge er basert på selvredningsprinsippet. Alle har ansvar for å redde seg selv ut. Siden 2011 har Norge hatt åtte store tunnelbranner. Bare en rekke tilfeldigheter og heltemot har gjort at ingen har omkommet. Denne filmen er inspirert av disse hendelsene." This translates to: "There are over 1,100 tunnels in Norway. Most of them have no emergency exits or safe rooms. The tunnel safety in Norway is based on the self-rescue principle. Everyone has a responsibility to save themselves. Since 2011, there has been eight big tunnel fires in Norway. Thanks to random chance and heroism, no one has perished. This movie is inspired by these events."
The song that plays at 26:18, as the family drives into the tunnel, is "No Me Llames" , by Mazy - not listed in the credits.
Tis is the second time actors Thorbjørn Harr and Ylva Fuglerud plays father and daughter. The previous time was in the TV-series Kieler Street (2018). Although, in that series they play stepfather and stepdaughter.