Milwaukee Police are investigating a serious injury crash that happened on Sunday, January 14th, around 1:10 a.m. An Audi Q7 was traveling east on W. Forest Home Avenue. The vehicle left the roadway and struck a tree in the 1500 block of W. Forest Home Avenue. The driver, a 35-year old Milwaukee man, suffered serious injuries and remains hospitalized. A passenger in the Audi was uninjured. Speed and alcohol are suspected as factors in this crash and charges are pending.