An accident at a construction site near 3rd and 19th Street this morning at 8 a.m. has sent four injured workers to the hospital. AlertSF warns to steer clear of the vicinity of 3rd and 20th until at least 10 a.m., as there must be some obstruction of the roadway from the accident. Bay City News reports that the condition of the injured workers is not yet known, but they were taken to S.F. General. [BCN] Update: Three of the workers actually fell six stories into drying concrete and were seriously hurt. A fourth worker suffered minor injuries. This all happened at a six-story building under construction at 19th and Illinois. [CBS]