By Laura Trevelyan
BBC News, New York
Thousands of emergency workers became ill from Ground Zero
A US Congressional committee will vote later on a bill providing long-term healthcare for emergency workers who fell ill after working at Ground Zero.
Campaigners say 800 people died as a result of exposure to toxic materials at the site of the 9/11 attacks, and more than 10,000 are sick.
Thousands of rescue and recovery workers became severely ill after working in the debris.
Many have respiratory diseases and some have developed cancer.
Campaign for support
Paying the medical bills for their treatment is an ongoing struggle.
Campaigners and New York politicians have been calling on the US Congress to fund permanent healthcare for the emergency workers.
The health sub-committee of the House of Representatives will vote on Tuesday on whether to approve a bill which would provide $11bn (£7.3bn) of long-term healthcare.
The bill has been languishing in Congress, due to the big price tag and the lack of support from congressional members outside New York.
But campaigners say the bill has more backing than ever before, as 9/11 emergency workers continue to get ill and die.
If the bill does pass the sub-committee, it would then have to be approved by the full House of Representatives and the Senate.
This vote comes as 10,000 of the 9/11 rescue workers who became ill consider whether to accept a $650m settlement from New York City.