How did the building collapsed?

"Ahhh..." a scream was heard from Nia's room.

I rubbed my forehead from the noise. Slowly I walked towards the room, didn't enter but watched the situation by leaning on the door and folding my arm.

Nia was standing on the bed and murmuring," Shh...go away...go away."

I could see a mouse on the floor and the color fading from Nia's face.

"Ahem...I didn't know, the person who isn't afraid of a dead body would be afraid of a mouse?" 

"B, please chase out this mouse. When I was small it had bit my feet and I developed Musophobia* since then. ( Fear of mice and rats).

The mouse itself went out. "Everything is ok now. Take your mask off. I have only kept you alive somehow, take your remedy." I was going to leave, Nia spoke.

"B, stay for a while..." removing the skin mask off her face Nia spoke timidly.

I can't ignore her so dragged a chair and sat back. I can't act however I like when people are around me and I hate it.