聯通香港首宗「死機」意外喺2018年2月27日上晝10時50分發生，聯通嘅網絡操作中心發現咗大批客戶未能夠使用流動話音服務、短訊服務及流動數據服務。到下午1時，網絡操作中心先至開始搶修，下晝2時20分陸續恢復服務。下晝4時30分，所有服務回復正常。整個故障歷時5小時40分鐘，共138，150名客戶受影響，佔聯通香港客戶嘅15.78%。第二宗「死機」意外於3月31日上晝11時15分發生，情況同一個月前相似。到晚上18時45分，所有服務先至恢復正常，整個故障歷時7小時25分鐘，同樣有138，150名客戶受到影響。兩宗故障一共歷時13小時15分鐘。
The first crash occurred at 10:50 a.m. on 27 February 2018, when Unicom's network operation center found that a large number of customers were unable to use mobile voice service, SMS service and mobile data service. It was not until 1 p.m. that the network operation center began emergency repairs, and services were resumed at 2:20 p.m. At 4:30 p.m., all services returned to normal. The entire outage lasted 5 hours and 40 minutes, affecting a total of 138,150 customers, accounting for 15.78% of Unicom's Hong Kong customers. The second crash occurred at 11:15 a.m. on 31 March, similar to that of a month ago. It was not until 6:45 p.m. that all services were restored to normal, and the entire failure lasted 7 hours and 25 minutes, also affecting 138,150 customers. The two failures lasted a total of 13 hours and 15 minutes.