Except in plain and indisputable cases the questions of negligence, proximate cause and contributory negligence are questions for a jury. It does not appear from the petition as a matter of law that the act of the defendants was not negligent or that if it was it was not a concurring proximate cause of the injuries, or that the plaintiff was barred by his own negligence. If two acts of negligence are material factors in producing an injury and are closely connected with it, and one has not so intervened as to make it the preponderating cause, the two negligent actors are guilty of concurring negligence. The petition does not show that the truck of the defendants was parked first so as to bring into play the principle that the act of the other defendant might have been the preponderating cause by reason of the fact that he parked his automobile with the act of the other two defendants consciously before him. Callahan v. Cofield, 61 Ga. App. 780 (7 S. E. 2d, 592). See also Scearce v. Gainesville, 33 Ga. App. 411 (126 S. E. 883), and cit.; Bonner v. Standard Oil Co., 22 Ga. App. 532 (96 S. E. 573); Locke v. Ford, 54 Ga. App. 322 (187 S. E. 715); Longino v. Moore, 53 Ga. App. 674 (187 S. E. 203); Jones v. Wadley, 50 Ga. App. 351 (178 S. E. 172). The cases relied on by defendants in error, such as Cain v. Georgia Power Co., 53 Ga. App, 483 (186 S. E. 229), and Grier v. Williams, 68 Ga. App. 863 (24 S. E. 2d, 509), are distinguishable in that in those cases it was held that as a matter of law the injury was not caused by the negligence of the defendant in whose favor the court ruled, but by a supervening cause. There being no special demurrers, we think the petition was good as against general demurrers and that it is a question for a jury as to whether negligence of the defendants in error or the other defendant or both was the proximate cause of the injuries. Russell v. Central of Georgia Ry. Co., 119 Ga. 705 (46 S. E. 858), Milton v. Mitchell County Elec. Membership Assn., 64 Ga. App. 63 (12 S. E. 2d, 367), Hudgins v. Coca-Cola Bottling Co., 122 Ga. 695 (50 S. E. 974), and cit. Many other cases to the same effect have been decided by both this court and the Supreme Court.

The court erred in sustaining the demurrers.

Judgment reversed.