NEW YORK CITY ? The next-door neighbors of a New York doctor sued him Friday, claiming the violent explosion that turned his Manhattan town house into rubble this week damaged their cooperative apartment and forced them to leave it.

Investigators have been investigating whether Dr. Nicholas Bartha, the loan occupant of the town house during the blast, might have rigged the explosion rather than sell the town house as part of a divorce judgment favoring his ex-wife.

Attorneys for Niso and Sherry Benbasat and their son, Vidal, say the gas-fueled blast Monday blew out the windows in their sixth-floor apartment in the 20-story Cumberland House, firing glass missiles and pouring smoke into the flat.

The investigators said someone connected plastic tubing to a basement gas line, allowing vapors to flow freely for hours until it caused the building to blow up.