Essex Police have launched an urgent appeal for smartphone footage and are actively tracking digital broadcasts following a horrific accident involving a stolen industrial loading vehicle at Chalkwell Park in Southend-on-Sea.

The incident occurred shortly after midnight on Saturday when a large group of teenagers gathered in the park. A small articulated loading vehicle, which had been stolen from within the park grounds, was being driven by unauthorised individuals during what police described as an illegal joyride. The heavy machinery crashed, striking a teenage girl and causing her life-threatening injuries.

Emergency services rushed to the scene and the girl was transported to hospital where she remains in critical condition. Paramedics worked at the scene to stabilise her before transfer. The park was immediately cordoned off as officers secured the area and began their investigation.

Investigators have confirmed that multiple onlookers recorded the entire sequence on their mobile phones. Police are now urgently seeking all footage of the incident, particularly any videos that show the moments leading up to the crash, the vehicle being driven erratically, and the immediate aftermath. Authorities are also tracking a specific digital broadcast that was shared on private networks just minutes after the collision, in an effort to identify everyone present and involved.

Two teenagers — an 18-year-old man and a 17-year-old boy — have already been arrested on suspicion of theft of a motor vehicle, dangerous driving, and other related offences. Both remain in custody as inquiries continue. Police believe more individuals may have been involved in the group that took control of the vehicle.

A mechanical log recovered from the loading vehicle shows that the suspects bypassed its security lock just five minutes before the crash. This evidence has strengthened the case against those arrested and is helping officers build a clearer timeline of events.

Chalkwell Park, normally a peaceful space used by families and walkers during the day, became the scene of chaos in the early hours. Local residents living near the park reported hearing loud engine noise and screams before emergency services arrived. The park remains closed while forensic teams complete their examination of the site and the vehicle.

Essex Police have made a direct public appeal: “If you were in Chalkwell Park last night and recorded any video or took photos, please send them to us immediately. Every second of footage could be vital to our investigation and help us understand exactly what happened.”

Detectives are particularly interested in any videos shared on Snapchat, WhatsApp groups, Instagram, or other private messaging apps in the minutes and hours following the crash. Officers are working with digital forensic specialists to recover and analyse any deleted or privately circulated material.

The teenage girl’s family has been informed and is being supported by specialist officers. A police spokesperson described her injuries as “very serious” and asked for the community to respect the family’s privacy at this time.

This incident has raised fresh concerns about youth disorder, vehicle theft, and the dangers of heavy machinery being used illegally in public spaces. Local councillors and community leaders have called for increased nighttime security in parks and recreational areas across Southend.

Anyone who was present at Chalkwell Park between 11:30 PM on Friday and 2:00 AM on Saturday is asked to contact Essex Police immediately, even if they did not record video. Witnesses can also submit information anonymously through Crimestoppers.

As the investigation continues, officers are examining CCTV from surrounding streets, analysing the stolen vehicle for fingerprints and other forensic evidence, and interviewing those already in custody.

The urgent hunt for smartphone videos reflects how digital evidence has become central to modern policing, especially in incidents involving large groups of young people. Police have warned that anyone found to have withheld relevant footage or obstructed the investigation could face charges.

The condition of the injured teenage girl is being closely monitored by medical staff. Updates on her progress will be released as appropriate.

Essex Police have thanked the public for their cooperation so far and emphasised that every piece of information or video helps them establish the full circumstances of this serious incident.