Plaintiff, Raul Bravo, individually and as next friend of Claudio Bravo, brought this suit to recover damages sustained by his son in a rubbish fire. Defendants appeal as of right from a denial of their motion for new trial.

The evidence at trial showed that on December 20,1965, the resident manager of the apartment complex, where plaintiffs resided, which was owned by defendants, started a rubbish fire near the community house area. While the fire was unattended, Claudio Bravo, age four, ventured too close to the flames and, as a result, suffered second and third-degree burns to his left leg.

Defendants’ first and second assignments of error concern the testimony of Sergio Bravo, the nine-year-old brother of the injured boy. This witness was not sworn, but was permitted to testify after examination by the trial court pursuant to MCLA §600.2163 (Stat Ann 1962 Rev § 27A. 2163). The witness testified that he and his brother had been playing with the fire when Claudio put his foot into *213 the flames. On cross-examination the witness made conflicting statements as to whether his testimony was prompted by his parents and their attorney.

Defendants made no objection to the jury instructions regarding the weight of this testimony. On appeal defendants charge that the trial court erred in failing, sua sponte, to strike the testimony and in failing to properly caution the jury.

The statute provides that the testimony of a child shall be given such credit as the court or the jury deems it deserves. People v. Minchella (1934), 268 Mich 123. The jury instruction was in accord with the holding in People v. Strunk (1968), 11 Mich App 99. In absence of timely objection to the competency of the witness to testify or a request for a more specific instruction pursuant to GCR 1963, 516.2, we find no error.

Defendants also charge that the trial court erred in limiting the scope of cross-examination of this witness. Defense counsel started a line of questioning as to whether the two boys, both under age seven at the time of the injury, had been told by their parents of the dangers of fire. The trial court ruled that questions which tended to show contributory negligence on the part of these children, or parental neglect, would not be permitted.

An infant under seven years of age is incapable of contributory negligence. Baker v. Alt (1965), 374 Mich 492. That issue was properly ruled out of this case. The injection of parental neglect would have been reversible error. Elbert v. City of Saginaw (1961), 363 Mich 463, 482, per Black, J., concurring; Lapasinskas v. Quick (1969), 17 Mich App 733. The trial court’s ruling did not preclude questions of whether another intervening or superseding cause was a proximate cause of the injury or whether *214 defendants were gnilty of causal negligence. We find the ruling proper.

Defendants’ third assignment of error centers on the applicability of the Michigan housing law 1 to the case at bar.

Plaintiffs alleged a violation of the section of that statute dealing with the duty of the landlord to keep the premises clean and that such violation constituted negligence per se. MCLA § 125.474 (Stat Ann 1969 Eev § 5. 2846), reads, in part, as follows:

“Every dwelling and every part thereof shall be kept clean and shall also be kept free from any accumulation of dirt, filth, rubbish, garbage or other matter in or on the same, or in the yards, courts, passages, areas or alleys connected therewith.”

The intent of the legislature in its enactment of the housing law is specified in the act’s title:

“An act to promote the health, safety and welfare of the people by regulating the light and ventilation, sanitation, fire protection, maintenance, alteration and improvement of dwellings.” (Emphasis supplied.)

It is clear that the legislature intended to impose a duty on a landlord to keep his premises free from accumulations of rubbish as, inter alia, a fire-preventative measure. See Feldman v. Stein Building & Lumber Company (1967), 6 Mich App 180. It is clear that plaintiffs were within the class designed to be protected by the statute.

There was evidence from which the jury could find a violation of the statute. Such a violation would constitute negligence per se. Hardaway v. Consolidated Paper Company (1962), 366 Mich 190; Douglas v. Edgewater Park Company (1963), 369 *215 Mich 320. We find no error as to the treatment of this statute hy the trial court.

Defendants’ fourth assignment of error centers on the applicability of Detroit city ordinance No 167-E, Detroit Ordinances, Ch 57, entitled “Smoke Abatement Code,” to the case at bar.

Plaintiffs alleged a violation of that part of the ordinance prohibiting the open burning of rubbish without a permit from the Bureau of Air Pollution Control and that such violation would be evidence of negligence.

Defendants are correct in their assertion that the ordinance was intended to prevent air pollution. See Huron Portland Cement Company v. City of Detroit (1959), 355 Mich 227. It is also true that Detroit Charter,Title 3, Ch 1, § 17, provides that ordinances shall embrace only one object. Defendants concede that a violation of a smoke abatement ordinance would be evidence of negligence in a smoke inhalation case, but not where the injury is due to burns.

This argument overlooks the testimony of the Fire Marshal of the City of Detroit. The fire marshal is given authority, pursuant to Detroit Ordinances, Ch 23, art 4, § 19, to:

“[promulgate and enforce reasonable rules and regulations * * * for the reasonable protection of life and property against fire and explosion.” (Detroit City Ordinance No 733-F.)

The fire marshal testified that it was against department rules and regulations to openly burn rubbish or leave a fire unattended. He stated that no permit to burn rubbish could be issued by the Bureau of Air Pollution Control unless the fire department concurred. His testimony showed that the same standards of safety promulgated by the Bu *216 reau of Air Pollution Control were adopted by bis office to prevent fire hazards.

It is clear from this testimony that ordinance No 167-E was offered as a codification of the rules adopted by the fire marshal as a fire-preventative measure. The materiality and relevancy of the ordinance was established. It was for the jury to decide whether there had been a violation of an administrative rule and whether to regard such a violation as evidence of negligence. Douglas v. Edge-water Park Company, supra. Defendants’ failure to object that the ordinance was not the best evidence of fire department rules precludes further review.

Defendants also argue that the verdict was excessive. This Court held in Stowers v. Wolodzko (1969), 19 Mich App 115, that verdicts would not be set aside or reduced unless there is a clear lack of proofs or a showing of improper methods, prejudice, or bias by the jury. There is no such showing in this case.

Affirmed.