hawk?

[sheeshshe]

Yesterday my chickens were out in their run, and my silkie was outside of the run getting to know the hens. my chicks were in the covered crib outside as well. I was inside in the kitchen by the window where the chickens are. They chickens went nuts and sounded like something was attacking them. so I rushed outright away but didn't see anything. the hens were so scared that they went in the coop and didn't come out for at least half an hour. SO I know it was something. Does it sound like it was a hawk? Would a fox or something take off and disappear that quickly? it all happened in 5 seconds or less.i was out there in no time LOL. I wonder because I'm getting ready to add on to their run and I want to make sure I make it safe for the type of predator that might be trying to get them. my current run is fully fenced and covered with a wooden roof. I was going to try and get by with a fenced roof. I've never had a predator situation in 3 years, so I was going to make it a little less safe bc I felt like I could. just to try and save on some $. If it is a hawk, will they try and get through thin fencing on the roof? or do I really need something super sturdy for a roof like I have now?

I do let them free range for a couple hours in the afternoon usually.