A cyclist who saw Hackney teen Jack Susianta die in a canal today told a court of her confusion that police were not diving in to save him.

Hackney Gazette: Tributes at the scene where Jack drowned (Picture: Ellie Hoskins)Tributes at the scene where Jack drowned (Picture: Ellie Hoskins) (Image: Archant)

When Ailish Tynan arrived at the canal at Walthamstow Marshes in east London in July 2015, another onlooker told her “the police have chased that fella into the water”, she told St Pancras Coroner’s Court.

Ms Tynan did not see A-level student Jack go into the canal but saw him “treading water like he was trying to stay in one spot” as police looked on from the grassy bank.

Ms Tynan told the inquest into Jack’s death: “There did not seem to be any sense of urgency, which made me think: ‘Gosh, maybe he has got a knife,’ and: ‘Why is nobody doing anything?’”

The Metropolitan Police have denied claims they refused to save Jack, who the court heard yesterday had “karate-kicked” a hole through a window in his home and run to the canal while on a bad ecstasy comedown.

Ms Tynan added: “I assumed he was dangerous because no-one was going in to get him. There were about 10 policemen there.”

She saw police throw a rescue line “about 20 times” to Jack.

Hackney Gazette: Tributes at the scene where Jack drowned (Picture: Ellie Hoskins)Tributes at the scene where Jack drowned (Picture: Ellie Hoskins) (Image: Archant)

“There was an Italian guy who said: ‘I am a good swimmer,’ [but] no one did anything because we thought the police would do it,” she told jurors.

Finally a sculler approached and got to within a single stroke of where Jack had been before the teenager disappeared beneath the surface.

“I could not really say if he [Jack] got too tired, tried to get away or pushed himself under – except that it was so close. If he had waited two more seconds, he could have got it.”

During all this, Jack, who was a strong swimmer, never said a word.

Ms Tynan’s husband Keith McNicoll said an officer subsequently entered the canal with very careful steps in the water, but accepted he could not see if the officer was sweeping the canal bed with his feet for obstacles.

He also said he never heard the police tell anyone not to go in.

Hackney Gazette: Tributes at the scene where Jack drowned (Picture: Ellie Hoskins)Tributes at the scene where Jack drowned (Picture: Ellie Hoskins) (Image: Archant)

Jack was not splashing about and there was a “feeling of serenity” apart from the policewoman shouting for a rope.

But the rower, Sean O’Shea, praised the police and described the officer who waded into the water as “brave”.

Mr O’Shea, who estimates he has rowed more than 30,000 miles on the river over 20 years, described the water as “very dangerous”.

“You cannot tell how deep the river is,” he told the court.

Mr O’Shea said he could not save Jack as he had an injured shoulder and feared the teenager might grab and topple his unstable boat. This would have meant they both could drown.

Defending the officers, he said: “They were frantically trying to get him to get hold of the (rescue) ring. He instinctively seemed to be moving away from it.”

Hackney Gazette: Tributes at the scene where Jack drowned (Picture: Ellie Hoskins)Tributes at the scene where Jack drowned (Picture: Ellie Hoskins) (Image: Archant)

Those witnesses who thought the dramatic scene was quiet were probably in a more distant position because the buzz of the overhead helicopter made communication “almost impossible”, he noted.

Mr O’Shea recalled: “The helicopter was incredibly loud. My feeling was that if they were in radio contact, they should have warned (it) off.”

He said the police pleaded with him to assist and an officer said: ‘Please help him.’

“It was with a note of pleading and desperation in his voice – it was not just an instruction,” he added.

Mr O’Shea, who thought the man in the water was a criminal trying to escape police, rowed back to see if he could reach Jack before seeing him go down for a last time.

“I could see him about 50cm out of my reach,” he said. “I could see him, I think, from the top of his head, which was slightly back and across his forehead.

“I could see a few bubbles as he sank.”

Mr O’Shea described the boy as uncoordinated, suggesting he had inhaled water the first time he went under.

The inquest continues.