On November 02, 2017, about 1735 Pacific daylight time, a Beech B95, N9628R, was substantially damaged when it was involved in an accident near Las Vegas, Nevada. The flight instructor and pilot receiving instruction sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 instructional flight. The flight instructor reported that, before departing on the flight, the fuel quantity gauges indicated that the main fuel tanks were each about two-thirds full. He did not recall the amount of fuel in the auxiliary tanks. The pilot receiving instruction reported that, upon starting the engines before departure, the flight instructor commented, "that’s strange." When he asked, the flight instructor said the main fuel tanks were only one-quarter full. The pilot receiving instruction looked and verified that both gauges indicated about one-quarter full. He stated that the flight instructor said, "we can run on the auxiliary tanks." The pilots departed on the flight and, after performing air work, they initiated an instrument approach. About 10 miles from the airport, the left engine began to lose power. They continued the approach while the instructor attempted to troubleshoot the left engine, until about 6 miles from the airport, when the right engine began to surge, causing a "violent pitching and yawing." The instructor declared an emergency with the tower controller and subsequently chose to land on a golf course fairway. During the landing, the airplane’s right wing struck an obstacle which resulted in substantial damage to the wing. The airplane came to rest in a small lake, submerged in water. The pilots egressed from a rear window and swam to shore. Two Federal Aviation Administration inspectors responded to the accident site and noted no signs of fuel leaking and no fuel slick in the water around the airplane. Following recovery of the airplane the next day, the inspectors confirmed flight control continuity and noted that none of the fuel tanks contained fuel or water. The right main fuel bladder separated from the airplane during the accident sequence; no fuel smell was noted. The airplane was recovered to a secure storage facility for further examination. Both engines were examined, and no mechanical anomalies were noted that would have precluded normal operation.