Censor.NET reports referring to the Lviv city council deputy and activist Ihor Zinkevych's Facebok page.
A man, 33, was found dead. The police and rescuers arrived at the scene.
"A partition wall was destroyed, and the floor was damaged. There is a hole, or cracks, or even a dent in the 4th floor ceiling. Hot water is running through this hole and a couple at the 4th floor is pouring the water through the balcony onto the street with plastic tubs. The central heating pipes may have been damaged. There is a part of a window frame and numerous small fragments of glass lying on the pavement in front of the house. The electricity has been turned off for now. I would like to point out the efficiency of fire and medical crews that arrived just about three minutes after the explosion. Three police crews and an emergency gas crew arrived a bit later," he wrote.