MIAMI (CBS4) – Hip hop singer Sean Kingston has improved slightly but remains hospitalized at Jackson Memorial Hospital in Miami, more than a week after his jet ski accident.

His condition has been upgraded from critical to serious, according to hospital officials, who also say Sean is breathing on his own and walked for the first time Monday morning.

A statement released by the hospital said Sean thanks his family, friends and fans for their outpouring of prayers and well wishes.

Kingston has been hospitalized for more than a week after crashing his jet ski into a Miami Beach bridge. The singer and a female passenger were hurt when the jet ski slammed into the Palm Island Bridge.

A Good Samaritan, John Rivera, was on a boat near the bridge and saw Kingston under water after the accident. He jumped in the water and held him until rescuers arrived.

Kingston rose to fame with his 2007 hit “Beautiful Girls” and was also featured on songs by artists including Justin Bieber.