The accident happened around 5:30 Thursday night at terminal F.
It is still not clear what caused a US Airways worker to crash his electric tug through a window at Terminal F, but officials do not believe that is was an act of terrorism.
On Friday afternoon, two gates in Terminal F remain closed while crews worked to replace carpet and glass panels
Officials say airport service is not being affected.
The crash frightened many of the passengers inside the terminal.
"I was just walking out the terminal and there was a massive amount of smoke, and everybody scrambling," said Paul Christensen.
Passengers arriving and departing from the 38 gates at Terminal F say they were startled by the unexpected surprise.
Shattered glass covered the floor from the large ceiling to floor window along with anti-freeze and other fluids from the vehicle.
"We saw that a baggage tote cart had crashed through the gate and through the glass and there was a lot of smoke, and you could see anti-freeze and hydraulic fluid from the transmission just seeping all over, and there was a lot of smoke," Christensen said.
Some wondered if it was an act of terrorism.
"One of the first things is 'What happened?' Did someone try to do something? Was there some kind of shenanigans going on here? So it is concerning," said Mike Beringer.
Airport and airline officials say it was strictly an accident.
"It is under investigating, and we're not sure the exact cause of the incident at this time. We are investigating it," said Victoria Lupica, Philadelphia International Airport.
Airport officials have not identified the worker. He was taken to a local hospital with minor injuries.
No passengers were hurt in the crash, but many were understandably shaken.
"I travel 100,000 miles and this is the first time that I have seen anything like that," said Christensen.