A citizen of the United States of America may file a Form I-130, Petition for Brother or Sister as an Immediate Relative if the petitioner's parents are both deceased. If brother or sister of a petitioner with deceased parents are classified as immediate relative, they do not have to wait for a visa number. Immediate relatives are not subject to the immigration visa limit. This will allow the petitioner to be reunited with at least one of his/her Alien Relative.
To be eligible, the petitioner must be:
1) A citizen or a lawful permanent resident of the United States of America before his/her parents passed away.
2) The petitioner was unable to petition parents
3) Must provide evidence that both parents are deceased.
This should apply to any unapproved/pending petitions at USCIS.