A multistream plant has a definite advantage of achieving an overall lesser downtime as compared to a single-stream plant based on Partial Oxidation because the outage of individual stream does not necessarily put the plant out of operation. But the safety considerations in the design, operation and maintenance of a multistream plant should be all the more elaborate and well defined. Usually the multistreams have common utility sources and a number of interconnections provided for the side streams. The present paper is a case study of an incident that occurred in the Ammonia Plant when the maintenance work was in progress in one stream and the other two were under operation.