"The platform – which was already shut down for pre-planned maintenance reasons and remains shut down – had 128 personnel on board, all of whom were accounted for. "EnQuest is liaising with all relevant authorities as part of its response to the incident, and a detailed investigation into the cause is being undertaken." Last year, the company was served with an improvement notice by the HSE following an emergency shutdown was initiated after the presence of gas was discovered by three gas detectors.