A Montgomery County deputy sheriff critically injured in an on-duty crash earlier this week has died.

Deputy Jermyius Young, 21, died Friday night at UAB Hospital in Birmingham.

“Deputy Young was a fine law enforcement officer,’’ Sheriff Derrick Cunningham said in a press release. “He was loyal, unselfish and efficient.”

The deputy had worked with the sheriff’s office since he was 18.

The wreck happened at 7 p.m. Wednesday in the 4500 block of Hobbie Road. Young was on duty and driving his patrol vehicle at the time of the crash.

Additional details have not been released.

Young was taken to Baptist Medical Center South in Montgomery in critical condition. He was later transferred to UAB.

Cunningham said Young died Friday evening surrounded by his family.

Funeral arrangements have not yet been made.

Cunningham thanked the firefighters of South Montgomery County Volunteer Fire Department, Haynes Ambulance, and the medical personnel at Baptist South and UAB hospitals for their care of Young.

“Please continue to pray for Deputy Young’s family and friends during this tragic time in their lives,’’ the sheriff said.