Miami-Dade police and the U.S. Postal Service are investigating after a fatal accident in the parking lot of the Miami distribution center.

Miami-Dade detectives said Shelby Wing, 70, dropped his cellphone into a storm drainage ditch at the facility on 2200 NW 72nd Ave. on Tuesday morning. He was trying to retrieve the phone, when he somehow fell into the ditch and drowned.

"Earlier this morning, there was a fatal accident in the parking lot of the Miami Processing and Distribution Center," said Debra Fetterly, USPS spokeswoman. "Postal employees are deeply saddened by the passing of their co-worker who was a dedicated employee for more than 25 years.”

"He loved his job, loved his life, and a great, great man," said Wing's grandson. "Honestly, he's the best grandfather anybody can have, and I know it sounds cliche, but it's the God's honest truth."

Wing celebrated his 70th birthday two days ago, and he recently turned in papers to the Post Office indicating he planned to retire in a matter of weeks.

"That's the sad part," his grandson said. "He said, 'Two months -- two months and we're going to Georgia."

Wing's supervisors said later he an outstanding work ethic, who always did above and beyond his job duties. They said he always had a smile and kind word for everyone. 

Detectives believe this was an accident.