On August 11, 2000, about 2300 central daylight time, a Cessna 208B, N1116Y, piloted by a commercial pilot, sustained minor damage during taxiing when it impacted a standing Cessna 172N, N734WD, operated by a commercially rated flight instructor with a student pilot on board, on taxiway B at North Platte Regional Airport Lee Bird Field, near North Platte, Nebraska. N734WD sustained substantial damage. N1116Y was operating as a non-scheduled domestic cargo flight under the provisions of 14 CFR Part 135 and N734WD was operating as an instructional flight under the provisions of 14 CFR Part 91. Visual meteorological conditions prevailed at the time of the accident. N1116Y had an IFR flight plan on file and N734WD had a VFR flight plan on file. The three pilots were uninjured. Both flights were originating at the time of the accident. N1116Y was destined for Central Nebraska Regional Airport, near Grand Island, Nebraska, and N734WD was destined for Tri-County Airport, near Erie, Colorado. The Cessna 208B's pilot stated, "I saw the aircraft taxi toward the south west out of the grass, and then south to the taxiway. After doing paper work, I got into the airplane (time was 22:50) and started the airplane engine completed the checklist and turned on taxi lights and started to taxi from the ramp. The radio tuned to 123.00 and transmitted that Sub Air was taxing from the ramp to runway 12. I then noticed that the airport lights were not on. I thought this was odd because of the 172 which had taxied out. I stopped the airplane which was still on the ramp and switched the radio from 132.7 back to 123.00 and turned on the lights. I then switched back to 132.7 and called Denver center and received the IFR clearance. At this time I was just leaving the ramp. As I taxied onto the taxiway going East I was wondering where the 172 was because I had not heard any calls from it for take off. The airplane was light so powerlever was at idle and was not taxiing very fast, still could not locate the 172. Then all of a sudden I saw the rudder of the airplane. There were no lights on the tail of 172 that I could see. I applied the brakes and slid the wheels but the propeller cut into the tail of the 172. I stopped and the 172 taxied forward approximately 20 feet. I shut down the engine and got out of the 208. Two pilots were out of their 172 but the master switch was still on because I now could see the glow of the red nav light on the left wing on the ground. The strobe on the belly at the 172 was not on." The Cessna 172N's instructor stated, "We began our taxi without our taxi/landing light on, using only our beacon and position lights. ... While at the hold short line we performed our run-up and opened our flight plan. My standard procedures for switching to FSS while on a CTAF are to switch the transmitter to the frequency on which I'm about to talk, and monitor the CTAF simultaneously. We followed this procedure and while I opened our flight plan, I heard no traffic advisories on the CTAF. 30 seconds after switching back to the CTAF for transmission, I turned my head left to look at [my student]. Out of my peripheral vision I saw a red glow moving toward us from behind. At this point I turned completely 180 degrees to our six o'clock looking directly behind us. The sight I saw next was the most horrifying scene that I have ever witnessed as a pilot. Out of the red glow of what I can only assume was our beacon, I saw the intake and spinner of the Grand Caravan bearing down on us at an unbelievable rate. I moved my hand and head forward as quickly as possible in an attempt to firewall the throttle. This effort was futile because my student was on the brakes and didn't know what was happening. As it turned out, the Caravan hit us before my hand reached the throttle. The plane shook violently forward and to the right for no more than 2 or 3 seconds. By this time I had reached the throttle and moved us forward enough to be out of the other aircraft's way." A witness stated, "[The Cessna 172N] taxied out to taxi way 'B'. As he was leaving I saw that he did have his beacon on the tail flashing, this was about 10:40. Between 10:40 and 10:55 I finished closing up shop. At 10:55 I went outside to have a smoke and wait for 11:00 to roll around. As I walked outside, [the Cessna 208B] was on taxiway 'B' traveling at a moderate to slightly high speed. Nothing outrageous but he was moving along. Then I saw the impact. At first I didn't know what happened, if the caravan had blown a tire and the nose gear collapsed. It wasn't until I drove out there that I saw the 172 with the tail tore off that I realized what had happened." A navigation light assembly from the Cessna 172N was recovered from the scene. The assembly was sent to the National Transportation Safety Board's Materials Laboratory. The report stated, "...All of the glass had been broken away, and none of the filament remained attached to the deformed filament posts. For this reason, the condition of the filament could not be determined." See appended Materials Laboratory Factual Report. Black colored ground marks were found trailing behind the Cessna 208B's main tires. See appended photographs. At 2256, the North Platte Regional Airport Lee Bird Field weather was: Wind 160 degrees at 11 knots; visibility 10 statute miles; sky condition clear; temperature 30 degrees C; dew point 11 degrees C; altimeter 29.95 inches of mercury. The airport manager stated, "As you can see the airport safety inspection was made at 640am Friday and the lights were working. We had no reports that the taxiway lights were inop anytime that evening. The lights were on when I arrived at the accident site around 1145pm." See appended statement and safety inspection.