Original sentence: On April 20, 2010, an underwater blowout and subsequent explosion and fire destroyed the Deepwater Horizon rig owned by Transocean Ltd.and operating in the Gulf of Mexico under lease to energy giant BP, resulting in the largest oil spill in United States history
Edited sentence: On April 20, 2010, a fire destroyed the Deepwater Horizon rig owned by Transocean Ltd.and under lease to energy giant BP, who objected to mandatory use of acoustic remote control systems for blowout preventers