THE ACFT COLLIDED WITH A STREET LAMP WHILE PULLING UP FROM A LOW PASS OVER A DRY RIVER BED. THIS EXPERIMENTAL AMATEUR BUILT ACFT WAS OPERATING OUTSIDE THE PRESCRIBED BOUNDARIES FOR THIS ACFT. WITNESSES DISAGREED ON THE ENGINE SOUNDS. SOMEDESCRIBED THE ENGINE AS LOUD AND STRONG. OTHERS SAID IT WAS SPUTTERING AND MISSING. ALL AGREED THAT THE ACFT FLEW LOW (ABOUT 50-75 FT AGL) OVER THE RIVERBED. AFTER THE ACCIDENT BOTH FUEL TANK INDICATORS READ EMPTY. THE MAIN FUEL TANK WAS PUNCTURED. THE AUX TANK CONTAINED ABOUT 1/8 GALLON OF FUEL. NO FUELING INFORMATION COULD BE OBTAINED. THE FUELING FACILITY AT FALCON FIELD HAD NO RECORD OF ANY PURCHASE BY THE PLT. THE PROPELLER WAS METAL AND PRESENTED EXTREME TWISTING WITH MULTIPLE UNDIFFERENTIATED GOUGES AND SCRATCHES BOTH BLADES WERE BENT FOWARD AND THE TOP OF ONE BLADE WAS MISSING.