A six-year-old boy who was thrown from the 10th-floor viewing gallery at London's Tate Modern museum sustained serious injuries, including a bleed on the brain and fractures to his spine, legs and arms, a court heard Tuesday.

The boy, 6, who is a French national, was airlifted to a hospital by London’s Air Ambulance after plummeting five stories to a roof in the incident, which took place Sunday afternoon when the popular gallery was packed with visitors.

The 17-year-old male who allegedly threw the boy over the balcony appeared at Bromley Youth Court on Tuesday, where he was ordered to be held on a charge of attempted murder.

CHILD THROWN FROM TATE MODERN IN LONDON CRITICALLY INJURED AS POLICE SEEK MOTIVE

The teen, who cannot be named for legal reasons, wore a grey sweater and spoke to confirm his name, address, date of birth and nationality as British at the short court hearing, Sky News reported.

Emergency crews attending a scene at the Tate Modern art gallery, London, Sunday, Aug. 4, 2019. (Yui Mok/PA via AP)

The boy remains in critical but stable condition at an area hospital. Authorities said they don't believe the suspect and victim knew each other, and the incident was "being treated as an isolated event with no distinct or apparent motive."

“This was a truly shocking incident, and people will understandably be searching for answers," senior investigating officer DCI John Massey said in a statement on Monday.

CHILD THROWN FROM TOP OF LONDON'S TATE MODERN ART GALLERY, TEENAGER ARRESTED, POLICE SAY

Nancy Barnfield told the Associated Press she was at the gallery with her family when she heard a "loud bang," and then saw a woman screaming "Where's my son, where's my son?"

London police said a teenager was arrested after a child fell five stories at the Tate Modern art gallery. (Yui Mok/PA via AP)

Barnfield said a man on the platform was restrained by other visitors until police arrived. She said he "just stood there and was quite calm."

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Tate Modern, Britain's leading gallery of modern art, sits on the south bank of the River Thames and was visited by almost 6 million people last year. The 10th-floor terrace is part of a pyramid-shaped extension that opened in 2016 and offers panoramic views over London.

The gallery reopened Monday, but the viewing platform remained closed.

The Associated Press contributed to this report.