GOLETA, Calif. (AP) — California's U.S. senators say the response to last week's oil spill that blackened beaches and created a 10-square-mile slick on the Pacific was "insufficient."

Democratic Sens. Barbara Boxer and Dianne Feinstein called on federal regulators to provide more details on the activities and decisions by operator Plains All American Pipeline.

They say it apparently took Plains about 90 minutes after the oil spill near Santa Barbara was confirmed to notify the National Response Center, a clearinghouse that coordinates agencies involved in an emergency.

They also question why the line apparently lacked an automatic shut-off valve, and whether enough people were brought in to contain the mess.

The underground pipe leaked May 19, spilling crude down a culvert and into the ocean off the southern Santa Barbara County coast.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

A section of pipeline that leaked thousands of gallons of oil into California coastal waters has been removed for analysis.

Artealia Gilliard of the Pipeline and Hazardous Materials Safety Administration said Thursday that the section was extracted and will be wrapped in protective insulation before it is sent to a laboratory in Ohio for metallurgical testing.

Gilliard says the pipe will be accompanied by an inspector from the federal agency throughout the process to maintain the chain of custody.

The underground pipe operated by Plains All American Pipeline leaked on May 19, spilling crude down a culvert and into the Pacific Ocean off the southern Santa Barbara County coast.

Oil blackened beaches and created a 10-square-mile slick on the ocean.

Some birds and marine mammals have been found dead.