stolen 2009 Specialized Globe Carmel 3 700c

I locked my bike to a street sign outside the St. Paul Lutheran Church Office near 818 Port Street the morning of Mardi Gras day at about 9 a.m. I used a steel U-Lock and attached my neon green helmet to the lock. I took a car home later that day around 4 p.m., but checked to make sure my bike was still there before leaving. I returned to the sign five days later to see my bike, lock and helmet gone from the sign. My assumption is someone had to use a hacksaw on my steel U-lock in order to steal the bike. I found no evidence of the theft, like a discarded lock or helmet. I drove around several blocks in the area in case it was locked elsewhere, to no avail.