Colleagues of an ambulance driver killed when his vehicle collided with another ambulance in north Wales said they have been left "absolutely devastated" by the tragedy.
Three people are receiving treatment in hospital after the fatal crash in Pwllheli, Gwynedd, on Thursday.
The Welsh Ambulance Service NHS Trust (WAS) said an urgent response ambulance collided with a patient care service vehicle on a stretch of the A499 shortly before 3pm.
Seven teams of paramedics were scrambled to the crash site, including two air ambulances, three ambulances by road and two rapid response cars.
The driver of the patient care service vehicle was pronounced dead at the scene, the WAS said.
Three people travelling in the urgent response ambulance were taken to the Ysbyty Gwynedd hospital with serious injuries, they added.
WAS head of operations in North Wales, Sonia Thompson, said: "We were all absolutely devastated to hear about this tragic accident, and our thoughts are with everyone involved.
"We're doing everything we can to support our affected colleagues, and are working hard to understand what happened."
Richard Lee, the WAS's director of operations, added: "As an ambulance service we deal with road traffic accidents on a daily basis. These are always difficult for our staff to deal with, but even more so when they involve our colleagues.
"We have plans in place to support our staff in Pwllheli and the wider Gwynedd area over the coming days."
News of the tragedy was met with messages of support from emergency service providers from across the country and further afield.
The WAS said it had been overwhelmed by the "humbling and deeply touching" reaction adding: "Out of adversity comes strength. We are truly stronger together. Thank you."
London's Metropolitan Special Constabulary tweeted that their thoughts were with all those involved at the WAS as part of the "#999family".
The Northern Ireland College of Paramedics said it was "very tragic news", tweeting: "Our thoughts are with our @WelshAmbulance colleagues and their families this evening."
West Midlands Ambulance Service said: "Our deepest sympathies go out to our colleagues in @WelshAmbulance who lost one of their own in a crash today. #RIP."
Jim Hancox, aircrew supervisor at Midlands Air Ambulance's Strensham base, wrote: "Words can't express the sadness and loss our @WelshAmbulance colleagues will be feeling tonight. We stand shoulder to shoulder with you..."
The Dublin Fire Brigade tweeted: "Thinking of our colleagues in @WelshAmbulance and everyone affected by today's tragic events #999family."
North Wales Police appealed for witnesses with information to contact the Roads Policing Unit on 101, quoting reference number U060780.