PARTING SHOTS: 20-mile-long Gulf plume discovered

Here's our daily roster of stories that evaded full-on blog treatment:

• Scientists have found a 20-mile-long hydrocarbon plume trapped 3,000 feet under the water in the Gulf of Mexico, challenging the Coast Guard's assurances that most of the oil is gone. They say they're unsure how the massive plume will affect wildlife. (CNN)

• More bad news for BP: Transocean, the company that owned the oil rig that exploded in the Gulf, is accusing BP of withholding documents to block their investigation of the incident. (AP)

• Democratic allies are giving up on the message that health-care reform will reduce the deficit over the long term and are now encouraging Dems to say they will work to "improve" the law. (Politico)

• An American Airlines flight from San Francisco to New York was stopped after someone phoned in a hijacking threat. Two people were detained. (AP)

• A court monitor says a settlement is on the way for the 1,300 office workers who say they were made ill by unsafe work conditions near the Ground Zero site after the 9-11 attacks. (The Wall Street Journal)

• Some former Bush advisers are urging Republicans to take a softer tone on the proposed mosque and community center near Ground Zero. (The Washington Post)