The Lexus sedan struck the Second Haitian Baptist Church at around 8 p.m. Sunday, when there were about 200 people inside, Lt. Victor Medico said.
When officers arrived at the scene, church members used car jacks to lift the vehicle off of people who were trapped underneath, according to the News-Press of Fort Myers.
Investigators were looking into the crash even though they believe it was "an unfortunate traffic accident."
"Everybody was sitting and the service started and then 'BING' the car came in," said Jean Corjeles, who was in the church when the crash happened.
"So many people are injured," he said.
Medico said the driver, a young woman, told investigators she was looking for a parking spot when the car malfunctioned and it drove "straight into the building," adding that she said the car's brakes malfunctioned.
Even though the car drove through an exterior wall and into the building, the structure isn't in danger of collapsing, said both Medico and Benjamin Abes, Lee County's EMS operations chief.
Lee Memorial health System spokeswoman Mary Biggs said 18 people were taken to Lee County hospitals and one was discharged late Sunday. She said none required surgery.