EXHIBIT 2.1 FIRST AMENDMENT TO AGREEMENT AND PLAN OF MERGER AMONG NATIONAL SENIOR CARE, INC., NCARE ACQUISITION CORP. AND MARINER HEALTH CARE, INC. This FIRST AMENDMENT TO THE AGREEMENT AND PLAN OF MERGER, dated as of October 21, 2004 (this "First...Agreement and Plan of Merger • October 22nd, 2004 • Mariner Health Care Inc • Services-skilled nursing care facilities
