RAPAPORT... Petra Diamonds has halted production at its Williamson mine in Tanzania for at least three months following a wall breach.The pause will give the company time to build a new tailings storage facility that was already under construction before last week's incident at the site. The new facility shares a wall with the old one; this adjoining wall collapsed. "[Williamson]'s technical team with the support of members of Petra's South African technical team are working together on-site to resume production safely and in accordance with applicable standards and procedures," the miner said Thursday. "Detailed planning is underway to bring a new tailings storage facility into operation."To minimize the impact from the lost diamond production, the miner intends to bring forward planned maintenance work at the site, it noted.Analysts at investment bank Berenberg said they were incorporating a "conservative four-month halt" to Williamson operations - as well as costs of around $20 million - into their financial models for Petra. Meanwhile, Petra has confirmed that there were no fatalities as a result of the incident. Three minor injuries were reported and have been treated. The company's shares have fallen 12% since the initial announcement on November 7.Image: Dump truck filled with ore at the Williamson mine. (Petra Diamonds)