Collision at sea between two Navy vessels.

During training at sea, two missile carrier vessels crashed at rather high speed on November 14, 1991. One of the vessels (HMS Luleå) was seriously damaged by the other (HMS Nynäshamn), and one conscripted seaman was killed. Both vessels had a complete crew of 29 each, 15 of whom were officers. Informal support and formal debriefing sessions were performed during the first 2 weeks. The crews of both vessels were followed by questionnaire concerning the psychological stress reactions after 1 month and 6 months. The post-traumatic symptom scale and the impact of event scale were used for assessing the psychological symptoms and reactions.