A young sports coach had already been dead for an hour when text messages were sent to her concerned father, suggesting she was in trouble.

“Don’t ask why or call. Please come to the school now and pick me up,” the text read.

Her father replied “are you OK?” and checked the location of her phone, which registered as the school where she worked alongside 24-year-old Thijssen.

Jamie called his daughter’s phone twice but no one picked up.

Instead, he received a text saying: “All good just came trouble (sic).”

Counsel assisting the coroner Jennifer Single SC told an inquest into the pair’s deaths that Thijssen was the only person who could have sent the messages to Jamie.

Doing so caused the young woman’s family to suffer as they frantically tried to get in touch with her without any success, she said today.

When Jamie rushed to the school and tried to contact his daughter, his messages went unanswered and he was not able to search the site.

The extensive injuries to Lilie’s body and amount of blood in her hair meant she was unrecognisable when she was discovered by police in the gym bathroom before midnight.

Police were only able to identify the 21-year-old after looking at CCTV footage from the school, which was earlier shown at the inquest.

The footage showed an unsuspecting Lilie smiling and chatting casually with Thijssen before walking to the bathroom with her swimsuit in hand.

The pair had previously been involved in a casual, two-month relationship, but Lilie ended it five days before she was killed.

She looked at a sign blocking off one of the bathrooms – which Thijssen had placed there earlier in the evening – before entering the disabled bathroom.

Thijssen followed her and stood outside the bathroom with a hammer in his right hand.

He appeared to look directly at the CCTV camera before lunging into the bathroom two minutes later.

Thijssen bludgeoned her to death with the hammer inside the bathroom in a premeditated attack before he was found dead at the base of a cliff in Sydney’s eastern suburbs hours later.

One of the issues for the inquest to consider is whether his death was self-inflicted.

Single noted Lilie was happily interacting with Thijssen before her death and appeared to have no indication of what he would do.

“No matter how many times you see that footage, it is not easy to watch,” she said as her voice broke.

Security footage from earlier in the evening showed Thijssen alternating which hand held the hammer while practising the murder outside the bathroom.

He was also seen disabling the automatic sliding doors, in a move Single said was designed to prevent the school cleaners from disturbing his attack on Lilie.

As well as assessing the circumstances surrounding the deaths of Lilie and Thijssen, the inquest will examine coercive control and unacceptable behaviour in relationships, in an attempt to prevent similar deaths.