On 3 September 2010, the 300-ton failed blowout preventer was removed from the well and a replacement blowout preventer was installed.[90][91] On 16 September 2010, the relief well reached its destination and pumping of cement to seal the well began.[92] On 19 September 2010, National Incident Commander Thad Allen declared the well "effectively dead" and said that it posed no further threat to the Gulf.[10]