The report places some of the blame for the accident on BP but also on Halliburton and Transocean.[312] The report found that on 20 April 2010, managers misread pressure data and gave their approval for rig workers to replace drilling fluid in the well with seawater, which was not heavy enough to prevent gas that had been leaking into the well from firing up the pipe to the rig, causing the explosion. The conclusion was that BP was partly to blame, as was Transocean, which owned the rig. Responding to the report, Transocean and Halliburton placed all blame on BP.[313]