(CNN) Public works employees in Florida stumbled upon something they don't see every day: a small "claustrophobic" tunnel leading to a Chase bank, according to the FBI.

The Pembroke Pines public works employees responded to a report of a possible sinkhole near the bank on Flamingo Road on Tuesday night and discovered the tunnel, which was about 50 yards long, with a power cord inside and a small generator at the foot, the FBI said Wednesday.

"It's approximately 2-foot, maybe 3-foot in diameter. It's very small, it's very claustrophobic," FBI Miami Special Agent Michael D. Leverock told reporters.

The tunnel was near a wooded area south of the bank, which is in a shopping complex across the street from the tunnel's entrance. The tunnel didn't reach the bank, the FBI said, adding that it is investigating the discovery as an attempted bank burglary. No arrests have been made.

"They're heading towards the ATM. I don't think they were doing that for any other reason," Leverock said.

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