Two other people are slightly injured, according to Region Skåne.
The truck driver has been arrested on suspicion of a traffic violation. The truck is believed to have crossed onto the wrong side of the road.
There are witness accounts that he drove over a wire fence, police spokesman Leif Fransson tells Sydsvenskan.
The road is closed in both directions, and according to the Swedish Transport Administration's forecast, it will not open until 8 a.m. on Thursday morning.
