Svitolina and Mertens match halted for unusual reason. What happened?

During the round of 32 at the grass-court tournament in Bad Homburg, Germany, Elina Svitolina faced off against Elise Mertens. The Ukrainian clinched the opening set 7-5, but play was brought to a sudden stop at the very start of the second set.

A fan in the stands was taken ill, prompting an immediate medical response that is still ongoing.

The match has already resumed, but there are still no details about what happened in the stands.

As a reminder, the winner of this match will face either China's Xinyu Wang or Brazil's Beatriz Haddad Maia in the second round.