Observations of a burst of gamma radiation, starting at 201247 UT, 1972, May 14 are reported. The measurements were made with a 0.5 m2 actively shielded scintillator which was the front element of a double Compton telescope, during a balloon flight at an altitude of 5 mb from Palestine, Texas. The maximum intensity of the burst was 0.10±0.02 cm-2 s-1 above 1 MeV, and the duration was 3.5±0.4 min. The burst intensity during the first 2 min is constant to within 10%. No known electronic or detector malfunction could have produced this effect, and we believe it is a real event.