Nobel Prize-winning mathematician John Nash and wife Alicia were heading home from Newark Airport when they were killed on the NJ Turnpike. They had opted to take a taxi from the airport, because they had managed to get an earlier flight, so their pre-planned limousine wasn't there.

The Nashes were in a taxi—going towards their home in Princeton—on the NJ Turnpike when the driver, Tarek Girgis, tried to pass a Chrysler in the right lane from the left lane. Girgis then lost control of the cab, crashing into a guard rail in Monroe Township. The Nashes were ejected from the vehicle, and State Police said it did not appear that the couple was wearing seatbelts.

Girgis, who suffered non-life-threatening injuries, used to drive an ice cream truck and had only been driving his cab for two weeks: His son told the Post, "He started a new company ... I drive the ice cream truck now."

The Post also revealed that the Nashes' travel plans changed, causing them to take the taxi ride with Girgis. John Nash, 86, and Alicia Nash, 82, had come back from Norway, after receiving the prestigious Abel Prize. NYU professor Louis Nirenberg, who shared the prize, was on the same flight:

[T]he Nashes hailed a yellow cab back to Princeton after they switched their flight at the last minute and arrived in New Jersey five hours early, Nirenberg said...

Nirenberg’s daughter, Lisa Macbride, said John Nash borrowed her cellphone to call for his limo when she arrived at Newark Airport to pick up her father.

“The car service said, ‘We thought you were getting in five hours later.’ They didn’t really offer a solution,” Macbride recalled.

“I said [to the Nashes], ‘You could take a taxi’ — which now I feel sick about."

Nirenberg described the couple during their time in Norway, "They were in good spirits. It was a wonderful week."

While Nash shot to early fame with his groundbreaking approach to game theory, now known as the Nash equilibrium, he suffered from paranoid schizophrenia. Alicia Nash met her future husband when he was teaching at MIT and she was a student in the 1950s, but his schizophrenia emerged during their marriage. From NJ.com:

The voices in his head began to overtake his thoughts on mathematical theory, however, and he quit his job in 1959, when Alicia Nash was pregnant with their son. During this time, Alicia Nash had him involuntarily committed several times, including twice in New Jersey, at Trenton Psychiatric Hospital and Carrier Clinic. Her actions created a rift in their relationship and they divorced in 1962, but he often returned home. Alicia worked as a computer programmer for NJ Transit, to support both him and their son. They remarried in 2001.

A friend, Dr. Debra Wentz, CEO of the New Jersey Association of Mental Health and Addiction Agencies, said that the couple should be known as advocates for mental illness, "There are no words that can just truly capture the loss or what great people they were. They were heroes for so many reasons. They were faced with adversity and yet have given so much back to others."

Their son, John Charles Nash, known as Johnny, also has schizophrenia (Nash had an older son, John David Stier, from a prior relationship); Alicia Nash wondered in 2009, "When I am gone, will Johnny be living in the street?"

Nash's struggle and his wife's support, which led him to receiving the Nobel Prize in 1994, became the subject of the Oscar-winning film, A Beautiful Mind, which itself was based on the biography by Sylvia Nasar. Nasar told the Washington Post that the Nashes' life, after the book and movie, "was a mix of glamour and celebrity - and the day-to-day which revolved around Johnny, who by then was in his 50s and was as sick as his father ever was and entirely dependent on them... The first thought that I had when I got the news was, 'Oh my God, what’s going to happen to Johnny now?'"

Wentz told the Daily News that Johnny Nash is "in deep grief, he’s in great distress. He just needs some time and space. It is a shock, but he's dealing with it well. The other son is also very upset."