What is the fine-grained topic of the following text: On the 12th April 2017 Centrica Storage Ltd announced that injections at Rough, UK's biggest storage facility, will not take place until May 2018 at the earliest, following increasing concern about the condition of the majority of the wells. Only return the topic.
Suspension of injections at Rough, UK's biggest storage facility by Centrica Storage Ltd due to well conditions.