The following was provided by the State via facsimile:
A moisture density gauge was being used at a construction site in Glendale, CA (near the Water Department and the Los Angeles River). (CPN, model MC3, serial number M36097108). The gauge user had placed the gauge into a box (plastic milk carton) which was then going to be passed down into a trench where it would be used. There was a delay and the box with the gauge inside were placed on the edge of the property waiting to be used. According to [the licensee], the gauge user went to the bathroom, but the other workers were aware of the location of the gauge. At the same time a front loader truck was moving several large pieces of metal. The pieces vibrated off and dropped onto and crushed the gauge.
[The licensee] said the sources appeared to be intact, however the plastic gauge housing was destroyed and the lead shielding leaves that normally surround and shield the end of the source rod (where the Cs-137 source would normally reside in a shielded position) were not in position anymore and were therefore not shielding the Cs-137 source now. [A] Los Angeles County Radiation Management Health Physicist, responded to the site to do an evaluation and to survey the source. The sources were intact and undamaged. There was no contamination. The dose rate at 1 foot was 20 milliRoentgen per hour (mR/hr). The end of the source rod was shielded and the remains of the gauge were placed into the transportation case. The gauge was transported by the RSO to Maurer Technical Services (the CPN manufacturer representative) [Deleted] so it can be shipped back to the manufacturer for disposal. The highest dose to any individual from this event was probably less than 5 millirem total. Corrective actions: The RSO will give refresher training to all gauge users to review their existing policies and procedures - gauge users are to have control over the gauge at all times.
CA report number: 030207