It wasn’t supposed to stop in Rockdale, and for most of last week it looked like Union Pacific’s No. 844 steam engine wasn’t even coming through Rockdale, but both of those things happened Thursday afternoon. The “Living Legend,” commissioned in 1944 as one of the last steam locomotives, was in Texas to attend 150th anniversary observances by Union Pacific, but had serious mechanical problems and fell far enough behind schedule that the railroad sent other engines to the festivities. But No. 844 made it to the historic I&GN Depot-Museum about 3 p.m. Thursday en route to extensive maintenance work in Georgetown. The unscheduled stop delighted a group of hastilyassembled train buffs.