Small aircraft flight instructor reported an near midair collision in the cma airport pattern.

Attributes
ACN	1650184
Time
Date	201905
Place
Locale Reference	CMA.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft
Operating Under FAR Part	Part 91
Flight Phase	Final Approach
Route In Use	VFR Route
Flight Plan	VFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Route In Use	Other VFR Pattern Downwind
Flight Plan	VFR
Person 1
Function	Instructor Pilot Not Flying
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Flight Instructor Flight Crew Commercial
Experience	Flight Crew Last 90 Days 287 Flight Crew Total 17952 Flight Crew Type 8254
Events
Anomaly	ATC Issue All Types Conflict NMAC Deviation - Procedural Published Material / Policy
Miss Distance	Horizontal 25 Vertical 00

Narrative:

I was flying with a private pilot doing take offs and landings. Weather was perfect and light winds and my student and I were cleared for take off. Everything was normal on climbout up to our crosswind turn for left closed traffic. Upon reaching pattern altitude at 875 feet and just about to turn downwind we were faced with another aircraft joining the downwind and we experienced a very near miss. The control tower screamed out a tail number of another aircraft and told that aircraft to turn right immediately which of course didn't help us and then a scream from the tower to execute a right 360 degree turn to avoid traffic by which time we were in a head on situation.after following up with the supervisor of the control tower his explanation was to say sorry; but they were training new controllers and admitted the horrific mistake. Upon checking the tapes in the tower we realized that this incredibly bad decision by the tower was evidenced by the communication. My student was horrified and completely discouraged from flying again which is so regrettable.

Original NASA ASRS Text

Title: Small aircraft flight instructor reported an NMAC in the CMA airport pattern.

Narrative: I was flying with a private pilot doing take offs and landings. Weather was perfect and light winds and my student and I were cleared for take off. Everything was normal on climbout up to our crosswind turn for left closed traffic. Upon reaching pattern altitude at 875 feet and just about to turn downwind we were faced with another aircraft joining the downwind and we experienced a very near miss. The Control Tower screamed out a tail number of another aircraft and told that aircraft to turn right immediately which of course didn't help us and then a scream from the Tower to execute a right 360 degree turn to avoid traffic by which time we were in a head on situation.After following up with the Supervisor of the Control Tower his explanation was to say sorry; but they were training new controllers and admitted the horrific mistake. Upon checking the tapes in the Tower we realized that this incredibly bad decision by the Tower was evidenced by the communication. My student was horrified and completely discouraged from flying again which is so regrettable.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.