All 156 Dallas emergency sirens were activated more than a dozen times early Saturday morning. Officials don’t know who was responsible for the hacking, but they say it was someone outside the city’s system. The city has figured out how the emergency system was compromised and is working to prevent it from happening again. The system should be restored Sunday or Monday in time for thunderstorms that are expected to hit the area early next week, officials say. The largest surge came from midnight to 12:15 as 800 incoming calls caused wait times to jump to six minutes.”]