Aborted take off

Currently on flight AS 1327, SFO TO SEA.

After a delay getting out of the gate, we finally taxi to the runway. We punch it for take off, pick up some speed for several seconds but suddenly the pilots killed the engines and we experience some pretty intense decel. Pilots say there was a plane at the end of the runway. We actually taxi'd back to the gate so a lady could get off because she was freaked out. Totally understandable. It was intense.

My question is, how dangerous was this this? I fly A LOT but I've never experienced this before. We are fueling up to take off again and I can't help but feel nervous.