The San Diego Police Department’s Gang Unit continues to probe the stabbing case of a 21-year-old man in a North Pacific Beach neighborhood that followed an unrelated stabbing death of another man just more than a block away nearly 24 hours earlier. In the latter case, the victim was reportedly walking with his girlfriend shortly before 3 a.m. in the 1000 block of Diamond Street when a second man attacked and stabbed the male pedestrian twice in the back, said investigators. The suspect then fled the scene and the stabbing victim was rushed to UCSD Scripps Hospital for treatment, police said. Investigators have not yet determined the motive for the attack, and no description of the assailant was available. The incident occurred just one day after a fatal stabbing at Emerald and Bayard streets. Police spokesman Lt. Gary Hassen said the two crimes are unrelated. Hassen advised that anyone walking late at night or in an unknown area remain vigilant. “Be aware of your surroundings and be alert,” he said. Anyone with information related to the second stabbing incident is encouraged to call Crime Stoppers at (888) 540-8477.