Zoo keepers have launched an investigation to establish how five wolves escaped from their pen.
Three timber wolves were shot dead and two others recaptured after they escaped through a damaged fence at Colchester Zoo, Essex, yesterday morning.
One of the wolves which was shot was found beyond the zoo's perimeter after an eight-hour search.
Staff were said to be devastated by the deaths.
A zoo spokesman warned: "They are wild animals and in an unpredictable situation they would have posed a risk to the public."
Today zoo bosses said they were trying to establish how the damage was caused.
"Colchester Zoo management are holding an investigation today, and we have no further comment to make at this time," the spokesman added.
Click below to see Serena Sandhu's full report:
More top news
An escalating row over restaurant tips could see staff in one chain walk out on strike.
Actors Nigel Havers, Denis Lawson and Stephen Tompkinson have been talking to ITV News Anglia about the hit stage comedy 'Art'.
A police officer has been taken to hospital with serious leg injuries after being hit by a car in a Bedfordshire town.