One day after the major fire in Essen city center with three injured and 35 destroyed apartments, the cause of the fire is still unknown.

The fire site is not yet accessible due to the danger of collapse, said a police spokeswoman on Tuesday morning.

During the day it will be checked whether a new four-legged police robot with a camera should explore the scene of the fire.

The 35-kilo police walking robot was presented just a few weeks ago at an appointment with NRW Interior Minister Herbert Reul (CDU) in Duisburg.

According to an initial assessment by the fire brigade, the ruins of the residential complex are in danger of collapsing.

Therefore, investigators could not enter it on the day of the fire.

During the night of Tuesday, firefighters checked several times with a thermal imaging camera whether something was glowing, as a spokesman for the fire brigade described in the morning.

Again and again small embers appeared, which were extinguished.

At around 7:00 a.m., the emergency services reported "fire out," the spokesman said.

This will hand over the operation site to the criminal police.

128 people had lost their homes and in many cases their entire property as a result of the fire that broke out Monday morning.

They had to move to acquaintances or hotels.

The fire brigade worked all day on Monday to finally extinguish the fire.

After the end of the nightly extinguishing work, the fire brigade wants to dismantle the hoses laid at the scene of the fire in the course of the morning.