'Everyone is really upset'published at 12:05 BST
Harriet Whiteside, 36, has brought flowers from her garden to show her respects to the people who died and the emergency services who helped.
"Everyone is really upset by what happened," she says.
Summary
A teenage girl and woman in her 40s have died after getting into difficulty at an Essex beach
A third person is in hospital in a serious condition, Essex Police says - officers believe the group knew each other
Another three people were taken to hospital, the ambulance service says
The coastguard was called at about 17:35 BST on Wednesday - one witness says she saw three people appearing to get CPR on the beach
"It was absolutely horrific," the witness says. "I can't praise the emergency services [enough], it was beyond all belief, they worked so hard"
'Everyone is really upset'published at 12:05 BST
Police speak to people on the beachpublished at 11:58 BST
Police officers have returned to the beach and are talking to people.at the scene.
Yellow rose in tributepublished at 11:48 BST
A woman was seen putting a yellow rose down at the beach as a way of paying her respects.
Islanders 'trying to come to terms with it'published at 11:43 BST
BBC reporter Tom Larsen-Wright has been at the scene this morning
Speaking to BBC Essex's mid-morning presenter Ben Fryer, he said islanders had woken up trying to come to terms with what happened last night.
"You can definitely tell that something has been happening in Mersea Island."
He said emergency services had now left the scene and the beach was busy with families.
Beach getting busypublished at 11:31 BST
Zoie O'Brien
Image source, Jamie Niblock/BBCThe beach has started to get busier now with families and dog walkers arriving for the day. Many are aware of the tragic incident which took place last night.
Local people have begun laying floral tributes close the where the tragedy took place, praising the emergency services for their efforts.
Rita, 70, was tearful as she described the rescue operation.
She and neighbours from nearby flats rushed to the scene last night with blankets, hoping to help the emergency services and anyone who may have emerged from the water.
Her neighbour, she says, heard a man screaming and “couldn’t speak” about what he had witnessed when he returned from the beach.
Four people taken to hospitalpublished at 10:34 BST
We've just heard from East of England Ambulance Service about its response to last night's incident.
It confirms two people died at the scene, one person was taken to hospital by air ambulance and another three were taken by land ambulance.
A spokesperson said: "Following reports of multiple people in distress in the water at Sea View Holiday Park, West Mersea, we dispatched multiple resources including our Hazardous Area Response Team, critical care paramedics and two air ambulances.
"Sadly, despite best efforts, two patients could not be resuscitated.
"One patient was transported by air to hospital, and a further three patients were transported by road to hospital."
Coastal safety advicepublished at 10:14 BST
Ahead of the summer and during the recent heatwaves, the RNLI has promoted a number of water safety tips.
If you're heading to the coast, it advises:
- Remember to check the tide times and carry a means for calling for help, ideally in a waterproof pouch
- Don't jump into cold water from rocks or piers (known as tombstoning)
If you do get in trouble in the water, follow its Float to Live guidance:
- Turn on to your back and tilt your head back with ears submerged
- Relax and try to control your breathing
- Use your hands to help you stay afloat
- It's OK if your legs sink, we all float differently
Where is West Mersea?published at 09:51 BST
West Mersea is a small coastal town on Mersea Island, about 10 miles (16km) south of Colchester in Essex.
About 7,000 people live in the town on the western side of the island.
The sand and shingle beach is one of its main attractions.
According to the town council, the island becomes completely cut off from the mainland during a full and new moon.
Here is an aerial view of the beach this morning:
Witness describes 'absolutely horrific' scenepublished at 09:40 BST
Rita Coombs, who lives in West Mersea, says she saw emergency services treating a group of people on the beach.
She says three people appeared to be receiving CPR.
"It was absolutely horrific. I can't praise the emergency services [enough], it was beyond all belief, they worked so hard."
She says she tried to support the emergency services during the "nightmare that was unfolding".
"The feeling was we just wanted to go out and help. Our hearts were going out to these people fighting for their lives."
She said the whole island feels "very quiet" this morning.
"It's a very sad island at the moment.
"We're just sending our thoughts to the people that have passed and the people left behind. It's tragic, absolutely tragic."
Sadness and shock at the scenepublished at 09:29 BST
Tom Larsen-Wright
Image source, Tom Larsen-Wright/BBCI'm at West Mersea beach, where there is a feeling of sadness and shock.
Residents have told me they've never known such a big emergency operation on the island.
Locals were also quick to praise the community response, and the efforts the emergency services made to help those involved.
A bunch of flowers has been left on the beach.
Two more people in hospitalpublished at 09:21 BST
Essex Police has released an update to say two more people are in hospital, with "non life-threatening" injuries.
The force previously confirmed two people had died and a third was in hospital in a "serious condition".
We now know that five people were involved.
Appeal for informationpublished at 09:13 BST
Det Ch Insp Pitcher is appealing for anyone who was at the beach, who has not yet spoken to officers, to get in touch.
He said: "We are grateful to the people who have already spoken to us and helped with our inquiries.
"We would ask anyone who was at the beach at the time, and who has not yet spoken with officers, to please get in touch, to help us understand what happened.”
He also appealed for anyone with footage to get in touch with police.
All involved knew each otherpublished at 09:10 BST
Det Chief Insp Al Pitcher, from Essex Police, says officers believe the three people involved all knew each other.
"Today, our thoughts remain with the family members who are coming to terms with their loss," he said.
Third person in hospital in 'serious condition'published at 09:07 BST
Essex Police says a third person remains in hospital "in a serious condition" following the incident, which happened at about 17:35 BST on Wednesday.
The force said it was called to the beach after reports that several people had got into difficulty in the water near Seaview Avenue.
Two people died in incidentpublished at 09:03 BST
BreakingA teenage girl and a woman in her 40s died in the incident at West Mersea beach on Wednesday evening, Essex Police has confirmed.
High tide was at 18:47published at 08:41 BST
BBC Weather reported that high tide at West Mersea was due to be at 18:47 BST yesterday.
It predicted a height of 4.4 metres (14.4ft).
This relates to the height of the tide, measured above a fixed reference level used for nautical charts, and is not to be confused with the height of waves or depth of water.
We're still waiting for further details of what happened, but the Coastguard referred to it as a "tragic incident".
At the scene this morningpublished at 08:32 BST
A sole bunch of red roses has been left on the beach.
Coastguard tape remains in place but emergency services have left the scene after last night's response.
We are awaiting confirmation of the exact nature of the incident.
Image source, Tom Larsen-Wright/BBC
Image source, Lewis Adams/BBC'Clearly, something unusual occurred'published at 08:24 BST
Local MP Sir Bernand Jenkin says he is "sad and very shocked" about the incident.
"We don't think of West Mersea beach as a dangerous beach.
"I mean, there are tidal currents but thousands of people use it as this time of year and generally feels like a very safe place.
"We don't have the details of what happened... clearly, something unusual occurred but we'll have to wait and see what it was."
He praised the emergency services and said he expects the community will come together to support each other.
We are expecting an update from Essex Police shortly.
'We will mourn this'published at 08:15 BST
Image source, Tom Larsen-Wright/BBCClaire Douglas, whose house backs on to the beach, says the community "will mourn this", after an incident described as tragic by emergency services.
She says the noise from two air ambulances flying directly overhead was the first sign of a major incident.
"It's just so devastating to hear that something has tragically gone wrong last night.
"You just immediately knew it was something very, very serious.
"You just get caught up in the sort of panic thinking there's nothing I can physically do, you're just standing watching.
"My neighbour is an RNLI volunteer he immediately got called out. I haven't seen him but he didn't get in until late.
"Nobody left until they'd done as much as they could.
"It genuinely is a strong community... we will mourn this."
The scene last nightpublished at 08:00 BST
Our reporter Lewis Adams headed to West Mersea beach last night, when news of the incident emerged, and captured these images.
Full details of what happened are yet to be confirmed but we are expecting news from Essex Police shortly.
Image source, Lewis Adams/BBC
Image source, Lewis Adams/BBC
Image source, Lewis Adams/BBC
Image source, Lewis Adams/BBC
