I called 911 to request an ambulance for my daughter. Two minutes later a Fire Engine showed up. A few minutes later the ambulance arrived and took my daughter to the hospital. Did you make a mistake?
A. No, we sent what you needed!
Some medical emergencies are more time critical than others. Your daughter must have needed help as quickly as possible. The firefighters who came are at least first responders, some may even be EMTs. Depending on the situation and location, the fire department or police may be sent to make sure that some help or treatment can be administered before the paramedics arrive.