Two teenagers fell to their deaths from a balcony on Wednesday as they cuddled at a party to mark the end of their exams.
Anastasia Tutik, a 19-year-old Russian, and a Mexican known only as Miguel, 18, were in a clinch when they lost their balance.
The drop of more than 60ft from the sixth floor killed them instantly.
They were celebrating at a luxury apartment block in Deptford, south-east London, with fellow students from Bellerbys College, an international school which charges fees of up to £21 000 a year.
Witnesses described hearing a huge bang in the early hours.
Samson Oguntayo, 32, who lives in a neighbouring block, said: “The guy was lifting the girl and putting her on the bannister, he kept on doing it.
“You could see they were doing some really dangerous stuff.
“At some point friends must have come outside and they got down and came back inside and then came back out again. They started doing it again.
“You see people on the balcony doing all sorts of things and I just felt they will probably go back inside. The last thing I expected was to see them falling down. We just screamed.”
Mr Oguntayo said he ran to the scene and discovered both teenagers lying dead in a pool of blood on a stone patio.
He dialled 999 but paramedics could do nothing to save either teenager. Witnesses said the pair’s friends were hysterical.
Shradha Chaturvedi, 31, who lives on the second floor of the block, said: “I heard a very, very loud noise and a lady screaming.
“Initially I heard a boom and at first I thought a firework had gone off or something.
“My husband came down and there were two guys outside who were totally drunk.”
Alfonso, a fellow student from Mexico, said Miguel arrived in London a week ago. “They met at the party,” he added. “He liked her and she liked him so they went on to the balcony to make out - to kiss and cuddle. They were alone on the balcony.
“Miguel had come to London to take a summer course in English. He was from Monterrey and he wanted to study business.
“Anastasia was very pretty - slim, blonde with green eyes - but she was very intelligent as well. She was one of the top students in the class.
“She was studying A-levels and she was hoping to go to university in September. Miguel’s family are devastated. His parents are flying over from Mexico. They will arrive tomorrow morning.”
Anastasia’s parents, who live in Russia, are believed to be flying into London. Bouquets of flowers have been placed at the foot of Knights Tower, which has spectacular views of the Thames and Canary Wharf.
Detective Chief Inspector Helen Millichap, of the Metropolitan Police Service, said: “We believe this was a tragic accident.”
Bellerbys hosts up to 300 international students who study A-levels, foundation courses and other qualifications.
Principal Paul McGregor said: “We are supporting the families of the deceased through this very difficult time. Counselling services are available to all students and staff at the college.”
Earlier this year, 17-year-old Russian student Polina Artomonova died in her room at Bellerbys, reportedly after taking drink and drugs. - Daily Mail