OPINION OF THE COURT

Memorandum.

The order of the Appellate Division should be reversed, with costs, and the interlocutory judgment of Supreme Court reinstated.

*729The theory of the third-party complaint of Somco Fuel, Inc., was that the third-party defendant, 163 Eastern Parkway Realty Corp., the owner of the premises, was negligent in having improperly maintained and operated the heating plant, that its negligence was a substantial contributing factor to plaintiffs injuries, and accordingly that if plaintiff should recover against Somco, Somco would be entitled to contribution from 163 Eastern Parkway. At the trial on the issue of liability only, under a charge that it could hold 163 Eastern Parkway liable, inter alia, on a finding of its failure to keep the oil burner in a reasonably safe condition, the jury returned verdicts against both Somco and 163 Eastern Parkway and apportioned liability between them in the ratio of 75% against Somco and 25% against 163 Eastern Parkway. On appeal the Appellate Division modified and dismissed the third-party complaint on the ground that there was no proof of negligence on the part of 163 Eastern Parkway or that any act of omission or commission on its part was an actual cause of the explosion.

On the contrary, our examination of the record discloses that there was evidence that a master switch, adequate to disconnect the entire heating unit, was required by law to be maintained outside the boiler room but that the master switch in this instance did not disconnect the entire system because it did not shut down the preheater. There was also evidence that plaintiff, on observing excessive smoke in the hall outside the boiler room, threw the master switch outside the access door to the boiler room. On entering the boiler room he proceeded to the inside panel to the jackknife switch to cut off the preheater which had not been disconnected when he threw the master switch. When he pulled the jackknife switch, it generated an arc which ignited gas which had continued to flow through the system, an explosion erupted through the furnace door, and he was engulfed in flames.

In sum, there was evidence both of negligence on the part of 163 Eastern Parkway and of proximate causation. Accordingly, it was error to dismiss the third-party complaint.

Chief Judge Cooke and Judges Jasen, Gabrielli, Jones, Wachtler and Fuchsberg concur in memorandum.

Order reversed, etc.