Scientists are trying to figure out if a gas well that blew wild last week off the Louisiana coast is polluting the Gulf of Mexico.
The researchers gathered water samples about five miles from the rig Saturday. That's as close as Coast Guard officials allowed them to get. They also released long cylinders that will drift with the current, tracking the likely path of any contamination. The "drifters" have global positioning devices and transmitters.
As the researchers worked, federal and private vessels could be seen coming and going from the site.
Regulators say natural gas detectors and high-capacity water hoses were being installed Sunday on the rig that caught fire last week. Another rig was being readied to dig a relief well for a permanent plug.
Explore further: Hopes, fears, doubts surround Cuba's oil future