I was there Saturday as well, March 29th. Hypersonic didnt open until 2 in the afternoon, and i got to ride it once. Drop Zone did indeed go down, and i sat on the brick wall later in the afternoon in front of it to rest, and amazing what youll hear when all of maintenance and park engineers are around. According to them, and no this isnt rumor because i know what i heard, the problem with DZ was that the mechanism that actually pulls the seats to the top of the tower wasnt releasing, which is why the riders had to be lowered mechanically to the ground. It never ran again the rest of the day.
Lots of rides had down time that day...XLC was down till 2, Volcano went down that afternoon, as did the Flight of Fear, and Drop Zone.