UPDATE 3:54 p.m. EST: Creigh Deeds' condition has been upgraded to fair, according to the Associated Press.

UPDATE 12:15 p.m. EST: Virginia State Police spokeswoman Corinne Geller said authorities believe the incident occurred Tuesday morning, just before they received a 911 call at 7:25 a.m. The probe is still determining why Deeds was stabbed. Geller said the Virginia state senator made statements to authorities but wouldn't reveal what he said. She also wouldn't confirm earlier reports that Gus Deeds' fatal gunshot wound was self-inflicted.

"Investigators are working right now on confirming the motive," Geller said. "There's still a lot of work to be done."

UPDATE 11:08 a.m. EST: Citing Democratic sources, NBC Washington is reproting that Gus Deeds stabbed his father before shooting himself.

Original story:

A Virginia state senator is in critical condition and his son was shot dead, authorities said Tuesday morning.

"Virginia State Police are on the scene of an assault of a state legislator that took place Tuesday morning,” read a news release from the agency, referring to Virginia State Sen. Creigh Deeds, a Democrat representing rural western Virginia, according to the Richmond Times-Dispatch. "Sen. Creigh Deeds has been transported to U.Va. Hospital in Charlottesville for treatment of serious injuries sustained in the assault at his residence."

The release would only confirm that a second victim was dead at the home, but law enforcement sources confirmed to the Times-Dispatch that the deceased was Deeds’ son, Gus.

Deeds, 55, ran unsuccessfully for governor four years ago against Bob McDonnell; he also lost to McDonnell in the 2005 election for Virginia Attorney General. Deeds is in critical condition, according to the Times-Dispatch.

McDonnell issued a statement on the incident:

"In this tough and sad time, our thoughts and prayers are with the Deeds family. The news from this morning is utterly heartbreaking. Creigh Deeds is an exceptional and committed public servant who has always done what he believes is best for Virginia and who gives his all to public service. He cares deeply about Virginia, and the people of Virginia care deeply for him," the governor said. "I urge all Virginians today to join me in praying for a full and complete recovery for Creigh and for many more years of his public service to the Commonwealth. At this moment, our state unites in prayer for Creigh Deeds and his family."

The incident also came as a shock to U.S. Sen. Mark Warner, D-Va., who also served as the state’s governor.

“Stunning news from Bath County,” Warner tweeted Tuesday morning. “I am praying for @CreighDeeds and his family at this very, very difficult time.”