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JAKARTA, Indonesia (CNN) -- The main front left exit of an Indonesian plane that crashed and burst into flames this week failed to open, preventing some passengers from escaping, according to a leading crash investigator.
Twenty-two people perished in Wednesday's blaze and eight are still missing, according to Garuda Airlines. There were 140 passengers and crew on board.
The plane from Jakarta landed at Yogyakarta in central Java, about 500 kilometers (300 miles) east-southeast of the capital, but overshot the runway, careened into a rice patty field and caught fire.
Most of the 110 survivors were in economy class and escaped through the back left door. Other passengers, including those sitting at the front of the plane, used the left overwing exits, said Frans Wenas, a senior investigator at the National Transport Safety Commission.
"Our findings showed the plane had been damaged after hitting a dyke," Wenas told Reuters, referring to an embankment by the runway. "The hinges of the front door were broken.
"Probably, smoke entered from the front right side. Everything became dark after smoke went in, so they tried to find exits that could be seen."
Many of the plane's business class passengers perished in the fire, according to Garuda. Of the 110 survivors, 67 remain in the hospital while 43 have been discharged, the airline said.
As the investigation continued into the accident Friday, an Indonesian airline official told CNN the weather and runway conditions at Yogyakarta airport were safe for landing.
Garuda Airlines Pilot Association President Stephanus Geralduf Getitit told CNN the weather condition was clear on Wednesday and the runway was "okay for landing."
The pilot did say there were problems during the plane's touch down, however.
Getitit said the captain told him he felt the aircraft "sink badly" and decided to stop the plane on the runway. There is an "up and down slope in that area," he said.
Officials with Indonesia's National Transportation Safety Board have been in Yogyakarta since Wednesday in efforts to determine what caused the Boeing 737-400 Boeing plane to crash.
Two theories officials have been looking into was whether the accident was caused by equipment malfunction or human error, CNN's Dan Rivers in Yogyakarta reported.
One airline official said when the plane touched down he saw the front tire burst into flames, resulting in the blaze -- a possible equipment malfunction.
Another theory was that the pilot came in too fast and overshot the landing strip. Rivers said the airport is known for having a short runway, according to pilots there.
Getitit on Friday dismissed that theory, saying the runway's length was "okay -- it's around 2,160 meters."
Data recorders, or black boxes, from the flight have been sent to Australia for analysis.
Video shot by a cameraman who was on the plane and escaped showed both engines had been ripped off the wings and the top of the plane appeared to have burned away, resulting in a smoldering fuselage.
It is the latest in a series of recent transportation disasters in Indonesia.
On February 22, a fire broke out on a ferry carrying 300 passengers north of Jakarta, killing at least 13 people.
On New Year's Day an Adam Air Boeing 737 plunged into the Java Sea, killing all 102 people aboard.
Two days earlier, a passenger ferry sank in a storm, also in the Java Sea, killing more than 400 people.
An Australian Federal Police officer walks past the engine of the crashed Boeing 737-400 passenger jet.