Jodie Chesney’s boyfriend fought to hold back tears as he told the court how she collapsed in his arms after she was stabbed.
Friends of Jodie, who was fatally stabbed on March 1, shared emotional accounts at the Old Bailey of the moment their friend was killed.
Eddie Coyle met Jodie at Havering Sixth Form College in Wingletye Lane, Hornchurch. They had been going out for about three months.
On March 1, they met with four other friends at Romford Station and took the 174 to St Neot's Road.
Wearing a black suit with a purple tie, Eddie told jurors that Amy's Park, Harold Hill, was a place they often visited.
He said: "We usually chill there, drink some alcohol and smoke some weed." The area is "not very well lit" and they had to use their phone torches to see.
That evening, another member of their group bought cannabis and they shared a joint.
About an hour later two men came into the park.
"One had a white puffer jacket on. One was wearing all black and a bit taller," said Mr Coyle.
He described the atmosphere as a "bit tense" to have the two men sitting behind them.
Sometime later the men left and another two men entered the park. Mr Coyle said it was "very clear" that they were the same people.
He told the court: "I saw two men walking towards us from the side entrance. I saw them and thought it was odd.
"Both of them started running.
"One was a stockier build the other was taller and slimmer.
"The shorter one went through the gate the taller one hopped it. The taller one swung his arm out and then stabbed Jodie in the back.
"I thought he was going to punch her first.
"She was in shock at first - just started screaming continuously. She stopped screaming and she began to faint."
While Mr Coyle tried to catch her he saw the two men run off together.
The 18-year-old said: "She was wearing a thick jacket so we didn't know how bad the wound was at first.
"There was a lot of blood.
"After I cried out for help two neighbours came. They gave as much help as they could."
He described Jodie, from Dagenham, as "a great person, very funny, silly, sensible sometimes" and that he saw no reason why someone would want to harm her.
He added that she had been laughing moments before her death.
A close friend of Jodie's who had also been in Amy's Park on March 1 gave similar evidence saying that she saw no reason why someone would want to harm Jodie.
The teenage girl said the music they had been listened to paused and there was a two-second break between the songs.
"I looked over my shoulder and I've seen a black guy with a black puffer jacket," she said.
"I just thought it was the same guys from earlier.
"They opened up the gate and I heard this slashing noise.
"I thought they were taking our bags because they were scattered over the floor behind us.
"When it happened Jodie started to breathe heavily. That's when she started to scream and I stood up and started to look around."
Manuel Petrovic, 20, of Highfield Road, Collier Row, Svenson Ong-a-kwie - also known as Spencer - of Hillfoot Road, Collier Row, and two youths, aged 16 and 17, from Barking and Romford, were subsequently charged with Jodie's murder.
All four defendants deny murder.
Another of Jodie's friends, Bryce Henderson, 18, from Romford, told jurors he had bought cannabis from Spencer in Harold Hill two or three times, although he could not say what he looked like.
The day before Jodie's death Mr Henderson said he received a message from a friend advertising a strain of cannabis called Pineapple Express.
"We wanted to try it because we watched the movie a couple of weeks before and wanted to know if it was any good," said Mr Henderson.
He couldn't get in touch with Spencer and so he bought weed from another dealer, called Jade.
When asked about how much cannabis the group had smoked before Jodie was attacked, Mr Henderson told jurors that around 1.5g had been smoked - which is about three joints between the group of seven friends.
He added: "I would obviously say yes it was in our systems but we were all fully aware of our surroundings.
"We weren't impaired."
Prosecutor Crispin Aylett QC told the court that all four defendants were part of a plan to cause "at least really serious harm to someone, not necessarily Jodie, in that park".
"If the prosecution are right about that then it matters not which one of them actually stabbed Jodie, nor in fact who the second male in that park was alongside the stabber," he said.
"As you will readily appreciate, this was not an accident nor can any of the defendants remotely claim to have been acting in self defence.
"Instead the prosecution allege that whichever of the defendants it was who stabbed Jodie Chesney in the back to a depth of up to 18cm, he must have done so intending to kill."
The trial continues.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here