Story highlights The woman was not moving when she was found, fire department spokesman says

A woman falls down an elevator shaft at Fenway Park

Rescuers shut off power to the elevator to prevent movement

The woman suffered serious injuries

A 22-year-old woman was hospitalized after she fell down an elevator shaft at Fenway Park in Boston late Friday, authorities said.

The unidentified woman was transported to Beth Israel Deaconess Medical Center. Jerry Berger, a hospital spokesman, said he had no information on the patient, but the Boston Red Sox said she suffered serious injuries.

"Somehow (the) elevator shaft doors on floor 4 opened," the Boston Fire Department said on Twitter.

The woman fell into the shaft, landing on the roof of the elevator, the department said.

She'd fallen "anywhere from 20 to 30 feet," fire department spokesman Steve McDonald told CNN affiliate WCVB

"The firefighters went to the upper floors and were able to look down and see her," McDonald added. "She was not moving."

Firefighters cut power to the elevator after stopping it on the 2nd floor, the fire department said.

Rescuers did not wait for a ladder; they used a chair and boosted themselves up through a hatch to the roof. They immobilized the victim and lowered her through the hatch, the fire department said.

In a statement before Saturday night's game against the Detroit Tigers, the Red Sox said: "The Massachusetts Department of Public Safety and the Boston Police Department are working to determine exactly what happened. Due to the ongoing investigation, and out of respect for the family of the young woman who was injured, the Red Sox will have no further comment at this time."

The cause of the accident is unclear.

A state elevator inspector was called to the scene and Boston police will investigate, the fire department said.

The Red Sox lost Friday night to the Tigers 1-0. The incident occurred shortly after the game ended.