The mayor of Neath Port Talbot has died suddenly after collapsing at a public event she was opening.
Councillor Janice Dudley was taken ill after starting the Round the Pier swim at Aberavon Beach near Port Talbot on Saturday.
Organiser Bernard Donovan said she was taken to hospital but later died.
Plaid Cymru councillor Mrs Dudley had represented the Bryncoch South ward since 2004.
Mr Donovan said she had started the 49th annual swimming race at 17:15 BST on Saturday.
"We were all mingling around having photographs taken and chatting and she seemed in good spirits, " he said.
"About 10 minutes after the start of the race she strolled towards the sea front with another race organiser and it was there that she collapsed.
"There were lots of people watching the race and I understand someone took her to Port Talbot hospital, which is nearby, by car.
"We were shocked to find out she had passed away."
So sorry to hear of the death of @NPTCouncil Mayor Janice Dudley. Thinking of her family and sending love.— michael sheen (@michaelsheen) August 20, 2017
Politicians and her constituents have paid tribute to Mrs Dudley - who was known as "Mam Plaid" by Plaid Cymru members - was invested as mayor in May.
Councillor Rob Jones, leader of the council, said activities of the mayoralty would be suspended until further notice as a mark of respect.
"During her short time as mayor, but also as deputy mayor during the last civic year, Janice represented the county borough and the council with distinction at numerous events," he said.
Councillor John Warman said: "The news was tragic and has hit our council and the community hard.
"Councillor Janice Dudley was a hard working and dedicated councillor who carried the respect of everybody who had the pleasure to know her and will be sadly missed by us all."
Plaid leader Leanne Wood tweeted: "Newyddion trist / very sad news. Cwsg mewn hedd / rest in peace."
Jeremy Miles, Labour AM for Neath, wrote: "Saddened to hear of the death of @NPTCouncil Mayor, Cllr Janice Dudley. Her family, friends and colleagues are in my thoughts and prayers."
Actor Michael Sheen, who is from Port Talbot, tweeted: "So sorry to hear of the death of @NPTCouncil Mayor Janice Dudley. Thinking of her family and sending love."
Fellow councillor Rebeca Phillips, tweeted: "So sad to hear of the passing of Cllr Janice Dudley. Mayor, Cllr, glamour puss, friend. Cwsg mewn hedd x"
Friend @bethphill_ wrote: "A privilege to campaign with Janice Dudley but even more so to call her a friend. She always beamed at young people getting involved locally."
A privilege to campaign with Janice Dudley but even more so to call her a friend. She always beamed at young people getting involved locally pic.twitter.com/dRvGEtzwMv— bethan (@bethphill_) August 20, 2017