By Susan Daker Of DOW JONES NEWSWIRES HOUSTON (Dow Jones)--BP Plc's (BP, BP.LN) efforts to capture oil spewing from Macondo well in the U.S. Gulf of Mexico hit a major snag early Wednesday when an underwater robot collided with the containment cap, U.S. Coast Guard Adm. Thad Allen said. The snafu halted the oil collection efforts of the larger of two storage vessels, the Discoverer Enterprise, which has a capacity to capture 18,000 barrels of crude a day. The pause could last for a few hours or much longer depending on whether ice-like crystals called natural-gas hydrates are found within the cap. "They are checking the containment cap right now," Allen said during a news conference. "They will attempt to reinstall the containment cap and begin producing later on today." But if there are hydrates, responders will have to reinsert the pipeline connecting the vessel to the containment cap, "and that will take a considerable amount longer," Allen said. The other oil-capturing vessel on the scene, the Q4000, is continuing to flare about 10,000 barrels of oil a day, Allen said. Two people working on the oil spill response effort died, but none of the deaths were work-related, Allen said. One of the deceased was working on a vessel of opportunity in the Gulf Shores, Ala. area, Allen said. The other was a swimming-related accident. Allen didn't say where the swimming death occurred. On Tuesday, BP collected a total of 27,090 barrels, the company said on its website. The British oil giant flared 10,425 barrels of oil and captured 16,665 barrels of oil. These figures beat BP's numbers from Monday, when the company captured 25,830 barrels a day. -By Susan Daker, Dow Jones Newswires; (713) 547-9208; [email protected] Order free Annual Report for BP plc Visit http://djnewswires.ar.wilink.com/?link=BP or call 1-888-301-0513 (END) Dow Jones Newswires June 23, 2010 13:00 ET (17:00 GMT)