Two girls aged one and three have died along with their parents in a two-car crash near Fort William.
The family were in a Mini Cooper involved in the incident on the A82 at Torlundy just after 17:30 on Thursday.
Police confirmed the dead mother was aged 26 and the father was 25.
The 56-year-old female driver of a Ford Fiesta freed from the wreckage by firefighters was taken to hospital in Fort William with serious but not life-threatening injuries.
The A82 around the scene of the crash was closed for 11 hours to allow for a police investigation. Police Scotland has appealed for witnesses.
Supt Simon Bradshaw said the scene faced by police officers, firefighters and ambulance personnel on Thursday was "extremely challenging".
He said: "I would take this opportunity to thank everyone involved for their efforts in the face of such a distressing incident.
"Every loss of life on our roads is a tragedy but the impact on families, friends and entire communities after an incident like this cannot be underestimated. Our thoughts are with everyone who has been involved or affected."
Supt Bradshaw added: "An investigation is ongoing to establish the full circumstances leading to this tragedy and it would be wrong for me to speculate on the cause at this time.
"However, I would ask that anyone who was in the area last night, who may have seen either vehicle involved before the collision or who may have dashcam footage to please contact police 101, quoting incident 2942 of 20 February."
Fort William and Ardnamurchan councillor Andrew Baxter said the "thoughts and prayers of everyone in Lochaber" would be with those affected by the crash.
He said: "This is devastating news for the family and friends of those who have been tragically killed in this accident.
"What I have seen on local social media is great sadness."
Kate Forbes, SNP MSP for Skye, Lochaber and Badenoch, tweeted: "This is extremely sad news. Thinking of the families and friends who are dealing with the shock of all of this."