Image copyright Facebook

"It's incredible the difference one person can make in your whole life and how empty it feels without them," says Carolynn Burke.

The 29-year-old wipes a tear as she talks about her friend Kirsty Maxwell, 27, who fell to her death in Benidorm exactly a year ago.

Twenty girls were celebrating Carolynn's hen party and had enjoyed a drunken night out.

Now four of them have gone back to mark the first anniversary.

The women have been putting up posters, handing out flyers and talking to people to see if anyone has information.

Image caption Kerry, Leslie-Anne, Suzanne and Carolynn revisit the site where Kirsty fell and hand out flyers

The women, who are from Livingston, West Lothian, still don't know what happened leading up to her plunging from the 10th floor of a room of the Apartmentos Payma in the holiday resort.

Five men from Nottingham were in the room she fell from. They were questioned by Spanish police but never charged.

David Swindle, a former detective assisting the family, told Newsbeat: "The key to this, to me, is in Nottingham.

"There were a large group of men from Nottingham here, there were over 50 of them.

"Some of them were in the room with Kirsty before she died, and some were staying at the Payma Apartments."

Image caption Kirsty fell from the tenth floor of a room of the Apartmentos Payma

Kerry Langton, 27, walked home with Kirsty and put her to bed that night.

"We got home safe. She was in bed safe. That's the worst thing about all this, we did what we always do, we looked after each other.

"You think you're in your room, she's tucked up in bed, we were safe.

"There are so many 'what ifs'. But we were as sensible as we could have been and yet something as tragic as this still happened."

Image caption Kirsty with her husband Adam

Nobody knows how Kirsty woke up and ended up in another room.

Lesley-Anne Watson, 28, was a bridesmaid for Carolynn, along with Kirsty.

"That night we just had so much fun, having a drink and a dance, taking selfies.

"It's horrible looking back on them now. You never think that when you're taking those pictures that it'll be the last time you're going to have a picture taken with Kirsty.

"You think this isn't real. It's the strangest feeling ever."

Image caption Kirsty's family and friends have put up posters around the resort

Lesley-Anne says she was haunted by seeing her friend's body that morning.

"That Saturday morning I got woken by a banging on the door.

"There were police officers in the corridor.

"I walked round the apartment to the opposite side and looked out the window and Kirsty was just lying at the pool.

"That's something that I never ever thought I'd have to look at or have to see.

"That image for weeks, if not months, was in my head. Why two hours after it happened she was still lying there, I'll never know. I was in a state of shock."

"At first we thought it was a mistake. Everyone was in a panic," says Kerry.

"That's why we know people must have seen something," continues Lesley-Anne.

"We need people to come forward. I'm here for one reason, and that's to get answers. We're a close group and we are together here, even stronger."

Image caption Kirsty's friends Leslie, Kerry, Carolynn and Suzanne return to Benidorm in search of answers

Carolynn says she struggles with the small things.

"It's the calls, texts, tags in a Facebook post - you have to really remind yourself she's not here anymore.

"I look at everything all the time. All the pictures that we've got, and all the Snapchat memories that we have.

"I got a book made of all our WhatsApp conversations just because I was so scared of losing it, and that I would lose those memories forever."

Image copyright Facebook Image caption Kirsty with her friends on her wedding day

"She's always in my thoughts. She was hilarious, and most of the time when we speak about her we are laughing about the fun times but then it is tinged with sadness.

"At least the memories that we've got are the best, they are amazing.

"Watching her get married to Adam was one of the best weeks of my life, out in Cyprus. I've never seen such a beautiful bride, she was just gorgeous."

Image copyright Facebook Image caption Adam and Kirsty on their wedding day

Suzanne Lothian, 28, tells Newsbeat they are normal girls who were on a normal hen party.

When the girls found out Kirsty had fallen to her death, they couldn't comprehend what happened.

"It was absolutely horrendous, but very surreal. I couldn't understand and put the two together, I couldn't understand how this could have happened.

"We didn't know if she was alive, we were told an accident, we didn't know at first.

"When you're asking the police, can you tell me if she is alive? When the answer is 'I'm sorry but no' - everything crumbles around you. It was terrible."

Image caption Kirsty's aunt Angela joined the girls in Benidorm on the anniversary of her death

Kirsty's aunt Angela also travelled with the girls to help them raise awareness around the anniversary.

"It's been emotional, but positive, we've put up the posters and we've been speaking to people.

"We just want to find the answers. We're trying to get support from anyone who was here last year to come forward.

"It's quite upsetting to look up and know that's where my niece fell to her death. The void is just so huge in our family. That'll never be filled."

Image caption Kirsty's friends hope that by raising awareness in the resort, they'll get some answers over her death

People are being asked to change their profile picture on social media accounts to one of Kirsty to mark the day.

The girls also set up at Snapchat geofilter with #KirstyMaxwell on it, hoping people will use it and hear about what happened.

Follow Newsbeat on Instagram, Facebook and Twitter.

Listen to Newsbeat live at 12:45 and 17:45 every weekday on BBC Radio 1 and 1Xtra - if you miss us you can listen back here.