Taylor Swift bravely extinguished a fire in her New York apartment

Gracie told the outlet: "She was such a legend - I don't know how at this hour or in our state she knew what to do.

"We both had an insane cough from the fire extinguisher fumes for weeks."

The pals have recorded the collaboration 'Us' together, which is due for release on June 21.

As well as sharing her reaction to the songs on Taylor's latest LP 'The Tortured Poets Department', Gracie revealed it was songwriter and producer Aaron Dessener tinkering away in the studio that inspired them to do a track together.

She said: "Something caught our ear at the same time very hard and fast.

"So we ran to the piano and started writing this song ... I used to fantasise about that kind of a thing as a kid."

A little while back, it was revealed that the 'Love Story' hitmaker keeps her awards "on the fireplace, on top of the toilet" and even "in a cage".

The 'Karma' singer threw the doors to her townhouse open to some of her loyal supporters in recognition of their years standing by her and super-fan Tyler Conroy found her many accolades were dotted all over the property, rather than kept in one room.

He told the Daily Mail newspaper: "Taylor had the whole top floor. Everything was brown, it was in an old New York style with a red sofa and a nook.

"Her dad was sat there when I was there and told me they had watched 'Frozen' a few weeks before. It was so cute.

"I played with her pet cats, and it was then I noticed that there was a birdcage with a broken Grammy award in it. Taylor had broken it [after dropping it at the awards ceremony] and she wanted to look after it by putting it in the cage.

"[The awards] were all over the place, there were a couple on the fireplace. There was even one on the top of the toilet, I have never seen anything like that before. Most people have some potpourri or some flowers, but she had a Grammy award on her loo."

One of Tyler's favourite parts of Taylor's apartment was her hidden bathroom.

He said: "To get to [it] there is a secret door behind a bookcase. It's a kind of speak-easy."

Inside the bathroom, Tyler found it kitted out with monochrome towels, each embroidered with the initials 'TS'.

Taylor bought the $18 million seven-bedroom property from Sir Peter Jackson in 2014, and Sir Ian McKellen was staying there at the time.

Tyler said: "Her father told me when Taylor went to look at her apartment Ian McKellen was sat there at the dining table in his pyjamas."

The 'Blank Space' hitmaker later expanded the property, buying three units in the building next door for under $10 million each, combining the two top floors to create one 8,300 square ft apartment space.