(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.

Public works employees at first thought they had been called to a sinkhole.

The tunnel appeared to be a scene straight out of a movie. Or not.

"I would like to say I saw something like this in the movies, however, this hole is so small that ... it's unique," Leverock said.

He added: "You would not be afraid of small places for sure if you were doing this."

Police cut the fence line and found the tunnel's entrance covered by a wooden pallet, CNN affiliate WPLG reported.

Authorities believe more than one person likely dug the tunnel, apparently using pick axes, Leverock said. A winch and a small wagon used to haul away dirt, debris and rocks was found, he said. Police also discovered a pair of muddy boots, a small homemade ladder and a stool, according to WPLG.

"This is truly a unique case here," Leverock said.

Pembroke Pines police used a small rover to investigate the tunnel, which went under Southwest Fourth Street, WPLG reported.

Authorities don't know where the tunnel ends yet or when it was abandoned, Leverock said. Rainfall over the past few days may have caused it to collapse, he said.

The Pembroke Pines Department of Public Works declined to comment, referring questions to the FBI. The FBI released photos of the wagon and generator, hoping the public could help authorities track down the digger -- or diggers.

Authorities want to talk to them.

"So, if somebody's been bragging about this, somebody's seen this wagon, seen a generator and some folks who are talking about a tunnel, certainly give us a call," Leverock said.