D.C. Code § 2-412
Hereafter the District of Columbia shall not assert the defense of governmental immunity in any suit at law in which a claim is asserted against it for money only on account of damage to or loss of property or on account of personal injury or death caused by the negligent or wrongful act or omission of any employee of the District occurring as the result of the operation by such employee, within the scope of his office or employment, of a vehicle owned or controlled by the District: Provided, that in the case of a claim arising out of the operation of an emergency vehicle on an emergency run the District shall be liable only for gross negligence. Nothing contained in this subchapter shall be construed as depriving the District of any other defense in law or equity which it may have to any such action or give to any person, corporation, partnership, or association any right to institute or maintain any suit against the District which it did not have prior to July 14, 1960.
D.C. Code § 2-412