NEW YORK (AP) The utility facing multiple lawsuits over last summer's massive steam pipe explosion near Grand Central Terminal has filed legal papers saying New York City may be to blame. The legal action by Consolidated Edison is among at least 242 claims seeking a total of about $600 million related to the July 18 explosion, the office of city Comptroller William Thompson said Wednesday. The utility's $25 million notice of claim says the blast, which left a woman dead of a heart attack and injured about 40 people, ``may have been caused, in whole or in part, by acts or omissions of the city.'' It says city sewers, pipes and drains may have let cool water leak onto the hot steam pipe, touching off the explosion. Filing a notice of claim is the first step toward a lawsuit. But Con Edison spokesman Michael Clendenin described the utility's notice, filed Monday, as ``a routine procedural matter, necessary in the event the investigation determines that the city's infrastructure contributed to the steam rupture.'' City lawyers were reviewing the filing and declined to comment. But Mayor Michael Bloomberg said Wednesday: ``We do not believe that ... there's any merit to the claim. As far as we know, there is no reason to believe that anything the city did caused the steam pipe explosion and we will certainly study the papers like we would if anybody files a claim against the city. I assume it is just a procedural thing that they're doing and will disappear into the dustbin of history with time.'' Relatives of the woman who died, Lois Ellen Baumerich, also filed a notice of claim against the city and Con Edison on Monday, saying they intend to sue for $50 million. Baumerich, of Hawthorne, N.J., ``experienced stress-induced fear, anxiety and terror, leading in turn to acute physiological changes, manifested by signs and symptoms which included shortness of breath and excruciating pain in the chest, culminating in cardiac dysfunction, cardiac arrest and death,'' according to the claim. City lawyers were awaiting the Baumerich legal papers and will review them thoroughly, said spokeswoman Kate O'Brien Ahlers, adding: ``We recognize this is a very tragic case.'' Con Edison spokesman Chris Olert said the utility wouldn't comment on the family's action. Eighteen cases have been filed against Con Ed, Olert said. Not all involve people who were hurt; some are property claims, he said. The utility recently asked a court to consolidate the cases.