LAKE BUTLER, Fla. -

Authorities say three people including the gunman are dead and two others were wounded in a murder-suicide Saturday morning in Lake Butler.

The Sheriff's Office said 72-year-old Hubert Allen Jr., step-grandfather of NFL running-back C.J. Spiller, shot and killed former co-worker Rolando Gonzalez Delgado, 28, around 9 a.m. Saturday.

Deputies said Allen then shot and killed his former employer, 80-year-old Marvin Pritchett, owner Pritchett Trucking, while he was sitting in his truck.

A few minutes later, Allen pulled over where another former co-worker was driving a farm tractor, exchanged words with him and then fired one shot from a shotgun, authorities said.

That victim, 66-year-old Lewis Mabrey Jr., was in good condition and receiving surgery for a broken arm and other injuries.

Not long after that, Allen went to the company's headquarters on Southeast 6th Street and shot 44-year-old David Griffis in the stomach, the release said. Griffis was in critical condition.

Authorities said Allen then returned to his Lake Butler home and killed himself. Officials said he was a longtime employee of the company.

Investigators were working at the five shooting scenes late Saturday and interviewing witnesses and company employees.

The trucking company's website says it employs 400 people and owns hundreds of vehicles that operate around the country. It said Pritchett started the trucking company in 1980, ten years after purchasing a Florida timber business. The company's main number rang unanswered Saturday.

Officials said it was too early to discuss a motive for the shootings.

Channel 4 has a crew in Union County. Watch Channel 4 News and stay with News4Jax.com for updates on this story.