US Supreme Court justice Ruth Bader Ginsburg, who is 85, has been taken to hospital with three fractured ribs after a fall at court on Wednesday.
The court has said Bader Ginsburg went to George Washington University Hospital in Washington early on Thursday, after experiencing discomfort overnight.
In her absence, the court was going ahead on Thursday with a ceremony welcoming new Justice Brett Kavanaugh, who joined the court last month after a fiercely-contested nomination process.
President Donald Trump and new acting Attorney General Matthew Whitaker were expected to attend.
She previously broke two ribs in a fall in 2012 and has had cancer on two previous occasions, and a stent implanted to open a blocked artery in 2014.
Currently one of the nine Supreme Court justices, Bader Ginsburg has made history at numerous points in her career.
In 1970, co-founded the Women’s Rights Law Reporter, the US’s first law journal to focus exclusively on women’s rights and when she began teaching at Columbia University, she became the school’s first female tenured professor and co-authored their first ever casebook on sex discrimination.
Bader Ginsburg was appointed to the US Court of Appeals for Columbia in 1980 and remained there until 1993, when she was appointed to the US Supreme Court – becoming only the second woman to win a place there.
Supreme Court justices serve for life, unless they are either impeached or decide to retire.