Former New York Gov. George Pataki has suspended his presidential campaign activities after his 30-year-old son-in-law suffered a “life threatening” stroke aboard a plane on Tuesday.

According to a statement from Pataki's campaign, David Levy, who is married to Pataki’s younger daughter Allison, is in intensive care at Rush University Medical Center in Chicago. The couple had been traveling on Tuesday to Seattle for a vacation ahead of the birth of their first child, when Levy suffered the stroke on the plane. It was diverted to Fargo, N.D., before he was transported to Chicago.

“This episode is a shock to us all, as David, only 30 years of age, is a strong young man who enjoyed excellent health,” the Pataki campaign said in a statement.  “We are praying for his recovery and welcome everyone's prayers and good wishes.”

Levy and Allison, a journalist and novelist, have been married since September 2011. The story of their relationship, which began when they were undergraduates at Yale University, was featured in a lengthy New York Times article after the wedding. Levy is a physician, and they both reside in Chicago.

Pataki, 69, a three-term governor of New York, launched his 2016 Republican campaign for president in May.