That crashing sound you just heard was the thunderous collapsing of hearts that are from Washington Spirit fans.
Details of the signing are not available to the public.
Crystal Dunn is quoted as saying: (taken from the Chelsea FC website in the Sources below):
"Dunn said: ‘It’s a big personal challenge for me but I am ready to take this next step in my career. Playing for Chelsea is a unique opportunity for me to take my game to another level and I think the moment is right.‘I have only been to London once before but there is something that grabbed me about Chelsea. The whole family culture – the unity, the morale – is making it feel just like home.‘I’m excited because Chelsea has a large fanbase and their relationship with the men’s team alone is just incredible. I’m looking forward to the games and to seeing all the fans who come out and support and hopefully we can all help add to the growth of women’s football in England.‘I’m going to give my all. It would be a dream to play in the Champions League and I am ready to help out the team in any way. I’m excited to join my new team-mates and join forces with them.’"
For those of you worried that you may not see her on the U.S. National Team, Dunn had consulted coach Jill Ellis prior to the decision. This is Dunn’s quote to the Washington Post
"“I told her I want to do it but also am very committed to the national team,” said Dunn, a winger whose 14 U.S. goals in 2016 were third on the squad behind Morgan and World Cup hero Carli Lloyd. “Jill told me, if I was going to do it any year, it’s this year. It was a good feeling having her support. That was something very important to me, being able to feel as though I am part of the national team and not feel as though I am missing out on opportunities.“It’s a great deal, being able to do the national team and also have the experience of playing overseas.”"
Dunn told Steven Goff of the Washington Post the reason why she was leaving:
"Dunn said, “I would be lying if Kriegs leaving and Christine Nairn leaving isn’t something I thought about, but my decision to leave was far beyond the different changes happening with the Spirit.”"
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And she had been thinking about it for awhile (again, this is from the Washington Post):
"“I had in my mind even before the season ended that I wanted to play in Europe,” Dunn said. “It’s just the time in my career to take that option.”"
Speaking as an NWSL fan, I hate seeing her leave for Europe, but I wish her the best, and hope that becomes a star on the U.S. National Team. And who knows, maybe she will be back on U.S. shores for the 2018 NWSL season.