Rescue services were called out to an injured dolphin or porpoise on Morecambe beach.
Police, the RSPCA and Morecambe Coastguard were called to the stricken mammal after it was found injured on some rocks on the beach near Marine Road Central at around 2.30pm on Sunday.
Police said a vet was called and because the dolphin or porpoise had a severe head injury and other injuries, sadly it had to be put to sleep.
The incident was concluded by about 5pm that day.
Harbour porpoise and bottlenose dolphins have both been sighted in Morecambe Bay.