PARK SLOPE - A Park Slope couple says they are suing real estate giant Corcoran Group Real Estate for knowingly selling them a $1 million condominium that floods.

Harold Einstein and his wife, Jennifer, say every time it rains, the back door of their home busts open and lets in a rush of water, flooding their apartment. They believe the developer and Corcoran real estate agents were aware of the unit's defects and sold the condo, anyway.

A Corcoran representative says the company disagrees with the "discovery ruling" and intends to file an appeal.

A judge recently allowed an e-mail exchange between real estate agents and the developer to be used as evidence.