(CNN) -- Three members of a U.S. Navy helicopter crew were killed after their helicopter went down in the waters off San Diego, California, a Navy spokeswoman said Wednesday.



Rescuers are still searching for the two remaining crew members from the helicopter, which went down late Tuesday night, U.S. Navy spokeswoman Karin Burzynski said.



No further details concerning the deaths were immediately available.



Burzynski said the helicopter was operating from the USS Nimitz. The Navy received word that the helicopter went down around 11:30 p.m. Tuesday, she said.



It crashed about 20 miles off the Mexican coast, the Navy said.



Coast Guard spokesman Henry Dunphy told CNN earlier that Coast Guard helicopters and boats, as well as vessels from other agencies, were helping in the search.
Who did the Coast Guard search for? Where did the crash occur? How many people are missing after the crash? What are the Coast Guard using to search? Where did the copter crash? How many people are still missing? Who is using helicopters? What day did the crash occur?
the two remaining crew members the waters off San Diego, California, two helicopters and boats, as well as vessels from other agencies, It crashed about 20 miles off the Mexican coast, two remaining crew members U.S. Navy 11:30 p.m. Tuesday,
question: Who did the Coast Guard search for?, answer: the two remaining crew members | question: Where did the crash occur?, answer: the waters off San Diego, California, | question: How many people are missing after the crash?, answer: two | question: What are the Coast Guard using to search?, answer: helicopters and boats, as well as vessels from other agencies, | question: Where did the copter crash?, answer: It crashed about 20 miles off the Mexican coast, | question: How many people are still missing?, answer: two remaining crew members | question: Who is using helicopters?, answer: U.S. Navy | question: What day did the crash occur?, answer: 11:30 p.m. Tuesday,