MOUNT PLEASANT, S.C. (WCBD) - A portion of Highway 17 in Mount Pleasant was closed Saturday night as police responded to a collision with injuries. According to the Mount Pleasant Police Department, Highway 17 near Lexington Drive was shut down shortly before 10:00 p.m. as officers responded to the scene. The closure is expected to last "for an extended length of time." Drivers should find an alternate route and avoid the area if possible. Ne…