stolen 2013 Trek 8.3DS

My bike was stolen from outside my own apartment. I had a black master U-lock and the bike was locked through the frame and front tire to a red metal rail, which somehow the thief seemed to have sawed through to get my bike free. My helmet was also secured through the lock (using the helmet straps). The bike had a rear Sunlite rack for disc brakes with a black crate bunjee corded down to secure it. It had both a small red flashing red light hanging off the back of the crate. the front handlebar had a small flashing light as well as a reflector. The original bike seat was adjustable but I had the stem changed to a silver, locking one so it stands out as not original. Everything else was basically stock. Please help me get my bike back