FLOWER MOUND (CBSDFW.COM) — A Flower Mound Family is mourning after a medical emergency behind the wheel sent a father and his 8-year-old daughter plunging into the Flower Mound riverwalk Sunday night, July 14.

As Daniel Morrow’s sister and her four kids waited for him at the river walk, neighbors heard a car accelerate then watched Morrow’s SUV miss a turn and drive over the bank.

“I ran downstairs to see the car half-submerged in the middle of the lake,” Said Gail O’Connor who lives nearby. “I ran down there, there were four small children – and his sister was already attempting to get him out,” O’Connor continued. “She had the door open and was struggling with a rock to try and smash windows.”

O’Connor said that the sister screamed at her to watch her children because they can’t swim. “So I scuttled all the children back to the edge,” said O’Connor.

According to a family spokesperson Morrow’s sister saw him in the driver’s seat as the vehicle went off the road and she said he appeared to be having a seizure. Morrow’s family said he had a history of seizures – but hadn’t had one in eight years.

Within minutes, a Flower Mound police officer smashed the window with a crow-bar and pulled him out. He later died at the hospital.

Neighbors say their thoughts and prayers are with the little girl he left behind. “She was in total shock, she just said nothing and stared blankly, it was a tragic, tragic accident,” said O’Connor.

Flower Mound police said their thoughts are with the family during this time.