Norsk Luftambulanse (NLA) has 10 EC135 P2+ plus one BK117 C2 flying air ambulance missions in Norway. The missions are flown from eight bases in the southern part of Norway (the northern most base is Trondheim), and most probably the crashed EC135 flew in from the Lørenskog base 18 km/11 miles to the east of Oslo city centre. The crash site is 25 km/16 miles along the E16 (Sollihøgda).
https://maps.google.no/?ll=59.992333...05284&t=m&z=18