SAN ANDRES, Colombia – Authorities on Wednesday reopened the island runway where a jetliner crashed with 131 people aboard, clearing the way for flights after crews worked overnight to remove spilled fuel and fractured pieces of the plane.

Colombian President Juan Manuel Santos thanked the rescue workers, firefighters and police who helped passengers to safety as he visited the airport. Only one person on board the plane was killed when it slammed into the ground short of the runway Monday on San Andres Island.

"We're very proud of the way you worked," Santos told rescue workers at the airport.

The wreckage was moved to a hangar while investigators search for clues to the cause of the crash.

Both survivors and authorities called the low death toll miraculous.

Doctors on the island initially said one woman who died, Amar Fernandez de Barreto, may have suffered a heart attack. But an autopsy concluded that the 72-year-old woman was killed by blows in the crash and didn't have a heart attack, morgue director Dolana Navas told reporters on the island.

An 11-year-old girl with a brain injury was the most seriously hurt passenger and was in critical condition at a hospital in the capital, Bogota. Doctor Carlos Hernandez said the girl's brain trauma was very severe.

Of 51 passengers flown from the island to Bogota for treatment, nine had been released, Bogota Health Secretary Hector Zambrano said. He said others with minor injuries were also expected to be released soon.

It may take experts months to figure out what happened in the moments before the Aires airline Boeing 737 hit the ground and broke apart. Authorities say the crash happened so quickly the pilot didn't report an emergency to the control tower.

Survivors said everything seemed normal as the plane approached the airport in a thunderstorm. Suddenly the jet hit the ground short of the runway, the fuselage shattering and sliding onto the tarmac.

Investigators have been interviewing the crew to piece together the jetliner's final moments. They will also examine the flight data and cockpit voice recorders — a process expected to take three to four months.

Among various possibilities, authorities are considering whether a violent wind shift in the thunderstorm could have played a role.

Boeing and the U.S. National Transportation Safety Board will aid the investigation.