According to investigators, officers responded to a 911 call received at a residence, located in the area of S.W. 83 Court & S.W. 78 Street, in reference to two individuals attempting to open vehicle doors.  The home owner observed the subjects through his surveillance equipment, providing subject and vehicle descriptions.  As the officer arrived in the area, he observed a vehicle, matching the subject vehicle description, leaving the community.  The subject vehicle proceeded to travel northbound on South Dixie Highway.  The officer continued to follow the vehicle and notified South Miami Police Department of his location.  Once the subject vehicle approached the intersection of Grenada Boulevard and South Dixie Highway, the officer activated his emergency equipment in an attempt to stop the vehicle.  The driver accelerated the vehicle at a high rate of speed and immediately lost control, causing it to strike a tree in the median, redirecting the vehicle onto the southbound lanes.  The driver and back seat passenger were ejected from the vehicle and the front passenger remained inside.  Both ejected occupants were transported to JMH Ryder Trauma Center by Coral Gables Fire Rescue, where they are listed in critical condition.  The third occupant was also transported in stable condition.  A firearm was recovered on the scene.  It is undetermined if anything was taken from the victim’s vehicle at this time.  Later in the morning, reports of a stolen vehicle was received.  An investigation confirmed to be the vehicle driven by the subject.