Foyle Search and Rescue crews were involved in this evening's incidents.
Members of the public helped rescue a person rom the River Foyle this evening.
Foyle Search and Rescue (FSR) said they received an alert from the PSNI shortly after 7.30pm to say they had a report that someone had entered the water.
Police officers and a crew from the rescue charity arrived quickly on the scene where they discovered that members of the public had activated a lifebuoy and brought the person to shore.
The person was treated for cold water shock and removed to hospital by ambulance.
A FSR spokesperson said crews in the process of recovering the lifebuoy were diverted to another incident where someone had attempted to retrieve an item from the water placing themselves in danger.
The FSR Jet ski supported by the charity's boat returned the item to its owner on land.
The spokesperson added: "FSR volunteers would like to acknowledge the two members of the public who used the lifebuoy to bring the person ashore having spoken to them at the time. Appreciation to PSNI, and CCTV for their assistance with both incidents."
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