The bombing, which occurred during an Ariana Grande concert, left 22 people dead and 59 injured, many of which were children. Hayek revealed her daughter Valentina, 9, was planning on attending Grande's London concert dates later in the week, according to the Daily Mail.
"If it was in London, this concert, my daughter would have been in that concert. It's her favourite singer," she said. "She would have been there, with or without me. This is one of the reasons why I have not slept."
This realization brought tears to Hayek's eyes and shook her to her core. When asked by the moderator if she had a message for those effected by the bombing, the 50-year-old actress plainly said she still hasn't fully processed the tragedy.
'I'm not sure what to feel today, and I'm terrified and I don't know what to say to my daughter," she said "And I'm not going to pretend that I'm sorted out, that I'm very smart about it, because I'm still emotionally impacted.
"So do I have a message? No, I haven't processed it. I'm not going to fake something. I'm opinionated when I know what I'm talking about it. I don't even know where to begin here."
Hayak later took to Instagram to share another message to her followers.
"Today we mourn with you Manchester," she wrote. "The brutal and barbaric atrocity forced on Great Britain can only be described as heart breaking. May we unite in strength and send our deepest condolences to those who have lost a loved one."
On Monday night, Grande tweeted a message to her fans that expressed a very similar message. Like Hayek and many others around the world, she wasn't sure how to put her feelings into words.
"broken. from the bottom of my heart, i am so so sorry. i don't have words," Grande said.