Abstract: Front structure in a vehicle, comprising a pair of spaced longitudinal box-shaped lateral beams (2), to which explosive charges (10) are fixed. With the aid of retardation sensors (20), a control unit (21) and detonators (22), the explosive charges are triggered in a collision after a certain crumpling deformation distance of the front portion of the beams to weaken the beams and prevent buckling and thus extend the crumpling deformation distance to the beam section lying therebehind. The controlled unit is arranged to compare the signals from the retardation sensors and activate the detonators only if the difference between the signals is below a predetermined value indicating relatively symmetrical frontal collision.