Dang, thats sucks bigtime. The section of the SART between Harbor Blvd/Warner Ave. north to the bridge over to the golf course (just north of the propane yard) is considered gang turf, but its safe to ride during the day (plenty of people around). I suspect it was pretty deserted at 6:15 pm on a Friday evening (about sunset?), giving the local gangbangers ample opportunity to take advantage of someone coming by (like you). Its good you're OK. Get that police report filed with the Santa Ana PD and include the bike's serial number so you have a chance of getting your bike recovered.