Plaintiff, Jacquelyn Creighton, appeals after summary judgment in favor of defendants,, members of the Board of Police Commissioners of the City of St. Louis, entered on October 2, 1995, on her petition for personal injuries sustained when her vehicle was struck by a police vehicle operated by Officer John Sabin.
In her petition, Creighton alleged, 1) defendants were members of the Board of Police Commissioners of the City of St. Louis, employer of City of St. Louis Police Officers; 2) Sabin was a City of St. Louis police officer acting in his official capacity; 3) Sabin, as such a police officer, was the employee, servant and agent of the Board of Police Commissioners acting within the course and scope of his employment; 4) on October 28, 1991, Creighton was driving east on Switzer Avenue at its intersection with Riverview Boulevard; 5) at the same time, Sabin was driving his patrol car north on Riverview Boulevard; 6) the electric signal at the Swit-zer and Riverview intersection showed green in Creighton’s favor and red for north-south traffic on Riverview; 7) Sabin’s patrol car collided with Creighton’s car because Sabin was negligently driving at a dangerous and *249excessive speed, failed to give a signal or warning of his approach, failed to slow, stop or swerve, and drove in violation of the red light; 8) Creighton suffered, as a direct and proximate result of Sabin’s negligence, several injuries; and, 9) Creighton spent approximately $1,000.00 for medical care and treatment and will have to spend more in the future.
Defendants filed a motion for summary judgment on the theory of official immunity. In the motion, defendants alleged there was no genuine issue of material fact that at the time of the collision, Sabin was responding to an emergency call regarding a fatal traffic accident and he had his light and siren activated. Defendants alleged Sabin was entitled to official immunity because he was an officer “engaged in a discretionary act proceeding with the lights and siren activated.” They also alleged where there are “no grounds for recovery due to the alleged negligence of a police officer, and where the officer’s employer is sued under the theory of respondeat superior [as in this action], there are also no grounds for recovery against the officer’s employer.” In support of the motion for summary judgment, defendants filed a memorandum of law, an affidavit of Minnie Phillips, an independent witness and deposition testimony of Officer Sabin and Creighton.
Creighton filed a response but did not file counter affidavits. She argued there was a genuine issue of material fact whether: (1) Sabin was responding to a “fatal” accident and (2) Sabin was merely performing a ministerial act while violating department regulations. Creighton relied on Sabin’s testimony, he did not learn of the traffic death until hours after his collision with her car. She also relied on Sabin’s reference to the pursuit policy of the Metropolitan Police Department-City of St. Louis.
The trial court granted defendants’ motion for summary judgment. It found Creighton had failed to demonstrate any genuine issue of fact that:
THE POLICE OFFICER WAS RESPONDING TO A RADIO DISPATCH FOR AN AUTOMOBILE ACCIDENT WITH INJURIES; SUCH CALLS ARE PRIORITY ONE CALLS REQUIRING ACTIVATION OF LIGHTS AND SIREN; AND THE OFFICER WAS RESPONDING TO THE CALL WITH LIGHTS AND SIRENS ACTIVATED.
It concluded:
THE OFFICER’S ACTIONS IN RESPONDING TO THE CALL WERE WITHIN THE SCOPE AND COURSE OF HIS EMPLOYMENT, AND THAT THEY REQUIRED THE EXERCISE OF HIS DISCRETION IN DETERMINING SPEED, OBSERVANCE OF TRAFFIC REGULATIONS AND OTHER MATTERS GENERALLY RELATED TO THE SAFE CONTROL OF HIS VEHICLE. THE OFFICER IS, THEREFORE, ENTITLED TO THE PROTECTION OF OFFICIAL IMMUNITY FROM TORT LIABILITY; AND THE DEFENDANTS, WHO ARE SUED UNDER THE THEORY OF RESPONDEAT SUPERIOR, ARE, LIKEWISE, CLOTHED WITH SUCH IMMUNITY.
Defendants have responded on the merits without comment on Creighton’s reliance on an outdated standard of review in summary judgment cases. Creighton should be aware “unassailable proof’ that there is no issue of fact to be tried is no longer the standard. Her reliance on Swink v. Swink, 367 S.W.2d 575 (Mo.1963) is misplaced. In 1988, the Missouri Supreme Court amended Rule 74.04 removing the “unassailable proof’ standard. ITT Commercial Finance v. Mid-Am. Marine, 854 S.W.2d 371, 378 (Mo. banc 1993).
When considering appeals from summary judgments, we will review the record in the light most favorable to the party against whom judgment was entered. Id. at 376. Facts set forth by affidavit or otherwise in support of a party’s motion are taken as true unless contradicted by the non-moving party’s response to the summary judgment motion. Id. Summary judgment is appropriate if the motion and response thereto show “there is no genuine issue as to any material fact and that the moving party is entitled to a judgment as a matter of law.” Rule 74.04(c)(3).
*250As a governmental official, Officer Sabin is shielded from liability for torts arising out of his discretionary acts or omissions. Kanagawa v. State By and Through Freeman, 685 S.W.2d 831, 835 (Mo. banc 1985); Anderson v. Jones, 902 S.W.2d 889, 891 (Mo.App. E.D.1995). However, he may be liable for negligently performing ministerial duties. Id. A police officer driving on the public streets and highways in a non-emergency situation is not shielded from liability for the negligent operation of his vehicle. Brown v. Tate, 888 S.W.2d 413, 415 (Mo.App. W.D.1994).
Creighton’s first point on appeal confuses the concepts of “emergency vehicle” and “emergency call.” An “emergency vehicle” is defined in the statute as including “those vehicles operated by ... traffic officer.” Section 304.022.3(1) RSMo 1994. “Emergency call” is a separate concept. Section 304.022.4(1) provides “[t]he driver of any vehicle referred to in subsection 3 of this section shall not sound the siren thereon or have the front red lights or blue lights on except when such vehicle is responding to an emergency call ...” Section 304.022.4(2) permits the operator of an emergency vehicle to “[p]roceed past a red or stop signal or stop sign, but only after slowing down as may be necessary for safe operation; [and] ... [exceed the prima facie speed limit so long as he does not endanger life or property ...” The exemptions apply “only when the driver ... while in motion sounds audible signal by bell, siren, or exhaust whistle ... and when the vehicle is equipped with at least one lighted lamp displaying a red light or blue fight ...” Section 304.022.4(3) RSMo 1994.
The dispositive issue is whether, as a summary judgment fact, the police officer was responding to an emergency call when the accident occurred. The evidence regarding the nature and circumstances surrounding the officer’s “priority one” call to the accident scene was unopposed. On October 28, 1991 at 8:25 a.m., the officer received a call over his radio that the dispatcher was receiving multiple reports of an accident with injuries involving an overturned Jeep on Broadway. According to the police department regulations, an accident with injuries is a priority one call which means the officer is to proceed with lights and sirens. Officer Sabin’s response was to an emergency call. It is irrelevant that he did not learn the call involved a fatality until many hours after his own accident. The trial court correctly found, as undisputed facts, Officer Sabin’s vehicle was on an emergency call when he collided with Creighton.
Creighton also argues the court erred in granting summary judgment because there was a question whether the officer activated the proper emergency equipment or whether he was traveling too fast. The statute places limitations on an officer’s ability to operate his vehicle in whatever manner he deems necessary. It requires use of both fight and siren before disregarding traffic rules that bind all drivers. McGuckin v. City of St. Louis, 910 S.W.2d 842, 845 (Mo.App. E.D.1995). Once an officer complies with these two mandates, he brings himself under the protective umbrella of the statute and can then exercise his judgment in responding to the situation as the circumstances warrant. Id.
Officer Sabin and an independent witness alleged in testimony and affidavit that the police car’s lights and siren were operating at the time of the collision. These allegations were not opposed by Creighton’s testimony that she did not hear a siren. She admitted it was possible she might not have heard the siren because her radio and windshield wipers were operating. Her response was not sufficient to preserve a genuine issue of material fact.
“Genuine” implies that the issue, or dispute, must be a real and substantial one— one consisting not merely of conjecture, theory and possibilities. Too often, courts have confused “slightest doubt” with “slightest possibility.” To the extent that trial and appellate courts are of the impression that the “slightest doubt” standard defeats summary judgment when any doubt exists, no matter how unreasonable, the standard [has] been misapplied and is now abandoned. ITT Commercial Finance, 854 S.W.2d at 378.
*251The use of required emergency equipment was an undisputed summary judgment fact.
Creighton’s argument that the officer’s speed at the time of the accident remains a genuine issue of material fact is misguided. Creighton makes the same argument the plaintiffs made in Costello v. City of Ellisville, 921 S.W.2d 134, 137 (Mo.App. E.D.1996). She argues the language of the statute not only mandates an officer utilize his or her lights and siren, but that it also requires an officer operating an emergency vehicle to slow down when proceeding through an intersection and not to exceed the speed limit when it would endanger life or property. Id. at 137. We rejected this argument in Costello. In that case we found the provisions in the statute “merely suggest how the driver of an emergency vehicle should proceed depending on the particular circumstances surrounding him or her at the time.” Id. An officer’s decision determining what speed he or she can maneuver through an intersection against a signal or at what speed in excess of the speed limit he or she can safely travel under existing traffic conditions is an exercise of discretion. Id. It is in this exercise of discretion that an officer is shielded from liability by official immunity. Id.
The unopposed summary judgment facts support the findings Officer Sabin: (1) responded to an emergency call in his emergency vehicle, (2) had activated his siren and lights and (3) reasonably exercised his discretion in determining his speed and observance of traffic regulations. He was therefore entitled to the protection of official immunity from tort liability. Defendants were sued under a theory of respondeat superior. Any liability against them would be derivative of Officer Sabin. Because he can not be liable, neither can defendants. State ex rel. Conway v. Dowd, 922 S.W.2d 461, 463 (Mo.App. E.D.1996).
We affirm.
RHODES RUSSELL, P.J., and SIMON, J., concur.