WASHINGTON — Sen. Amy Klobuchar continued to press administration officials and oil company executives for answers Tuesday about the massive oil spill that is befouling the Gulf of Mexico and threatening U.S. coastlines.

At a Senate Environment and Public Works Committee hearing, Klobuchar said Americans still have no idea exactly how much oil is leaking daily into the Gulf as a result of the Deepwater Horizon oil rig explosion last month. The blast killed 11 workers and set off an environmental alarm.

"With each passing day, thousands of barrels of oil spill into the ocean, and the American people deserve to hear an honest assessment of when this disaster will be contained," Klobuchar said. "The scope of this disaster is truly staggering."

The Minnesota Democrat asked Environmental Protection Agency Administrator Lisa Jackson and Interior Secretary Ken Salazar about what steps were being taken to stop the leak, which some experts estimate to be as high as 70,000 barrels a day.

Klobuchar, who toured the Gulf area with fellow lawmakers May 7, also asked the officials what they were doing to prevent future disasters. And she said Americans want those responsible to be held accountable.

"This spill reveals a serious lack of safety surrounding the oil industry," Klobuchar said. "We must take fast action to stop this leak, ensure the responsible parties are held accountable for the damage they have caused and put the necessary safety measures in place so disasters like this never happen again."

At a separate hearing of the Senate Commerce Committee, Klobuchar again called for a full accounting from Lamar McKay, chairman and president of BP America, and Steven Newman, president and CEO of Transocean Ltd., whose companies were involved with the Deepwater Horizon. She also called on them to provide aid for affected communities.

McKay told lawmakers the entire industry was trying to figure out what caused the explosion and how to prevent such an accident from happening again.

"We understand that the world is watching and that we and our industry colleagues will be judged by how we respond to these events," McKay said in a written statement.

During the earlier hearing, Klobuchar said testimony last week by the oil company executives reminded her of "a group of kids who knocked a baseball through the neighbor's window — with none of the kids wanting to own up to their actions."

"But the consequences of these actions go far beyond repairing a window," she said. "The lives of 11 families cannot be repaired. The lives of thousands of families on the Gulf Coast have already been turned upside down, and the problem is still getting worse."

Klobuchar has co-sponsored legislation that would raise the liability cap for offshore oil disasters to $10 billion from $75 million.

On Monday, Klobuchar and members of the environment and public works committee called for a Justice Department probe.