An apartment explosion that cost three lives on Sunday was an intentional murder-suicide, police believe.

The explosion occurred at midday on Sunday on the fifth floor of an apartment building on Rahbeks Alle, which is on the border of Vesterbro and Frederiksberg.

“The preliminary investigation suggests that the 38-year-old man who lived in the apartment had done some preparatory actions that led to the explosion,” Copenhagen Police deputy inspector Lau Thygesen said, according to Jyllands-Posten newspaper.

In addition to the 38-year-old man, the other two deaths were of the manÂ’s 34-year-old former girlfriend and her 69-year-old father.

According to family sources, the pair had lived together until recently. In a written statement, the womanÂ’s family members stated that the couple had lost a baby over the summer and the ongoing pain from that loss may have led to SundayÂ’s fatal incident.

The tabloid Ekstra Bladet reported that the woman had come to the apartment to claim some of her belongings and had brought her father along because she was wary of the situation. Police, however, have not confirmed that theory, but did indicate that the woman no longer lived in the apartment.

All three individuals were transported to RigshospitaletÂ’s trauma centre following the explosion. The woman was declared dead shortly after arrival, while the two men died later in the day.

The female victim ran a well-known Copenhagen restaurant, although the establishmentÂ’s name has not yet been publicly released.

The police investigation into the explosion is due to continue today.