Just what caused the collapse last week of the overhead canopy at the old Dinky train station remains under investigation. But preliminary results reveal that the accident, during which no injuries were reported, was caused by removal of a section of the canopy, according to a spokesman for Turner Construction, the company working on Princeton University’s $330 million Arts & Transit project.

Turner Construction has been issued a $2,000 fine by the town for failing to obtain a permit for the demolition work. While taking down the canopy was in the site plan for the project, the proper permit was not obtained before the canopy came down.

The accident last Thursday drew local fire and rescue personnel as well as fire departments and rescue teams from neighboring communities. Five workers had to be accounted for, and there were concerns about students who may have been illegally crossing through the construction site. The search included video cameras, thermal imaging cameras, and specially trained dogs.

“On Thursday, September 19, LVI Demolition Services removed approximately two feet of the canopy that was connected to the Dinky station so as not to damage the building when the canopy was removed,” said Turner spokesman Christopher McFadden in an email on Tuesday. “After construction crews had left the site for the day, we received notification at about 4:30 p.m. that the balance of the canopy had fallen. Emergency personnel responded and confirmed that there were no injuries.

“While the investigation continues, at this time it indicates that the remaining support structure became stressed under the weight of the canopy and fell toward the decommissioned tracks. The canopy has since been safely removed and work has resumed at the project,” he said.

University spokesman Martin A. Mbugua said Monday that investigation is continuing into the accident and more information will be available at the end of this week.

Meanwhile, members of Princeton Council have called for a full exploration into what went wrong. “I think we should treat the accident as if someone was killed, because someone could have been killed,” Council member Jenny Crumiller said at the governing body’s meeting Monday night. “What permits were issued? What inspections were made?”

The town’s administrator Robert Bruschi called the accident “an anomaly,” adding that University and municipal staff have been working closely on the project. On the subject of permits, Mr. Bruschi said, “We’re discussing that with the University. Our professional staff is working on it.”

Council members Bernie Miller and Jo Butler echoed Ms. Crumiiler’s concern. “We have a responsibility to know what happened,” Ms. Butler said. “So when there is a report internally, it should be distributed to the mayor and Council.”

Renovations to the former Dinky station are being made as part of the ongoing Arts & Transit project, which is scheduled to open in 2017. The station has been temporarily relocated while a new terminal is being constructed some 360 feet south of the current station buildings, which are to be converted into a restaurant and cafe.

Questions about the accident were posed to Kristin Appelget, the University’s director of Community and Regional Affairs, following an update she gave Council about the construction project. The next major changes will come in mid-October when a temporary road is opened. The road travels northeast from Alexander Street near the temporary Dinky station and up to University Place, she said.

Alexander Street will be closed up to College Avenue from the construction site, and the portion of University Place leading to the old Dinky terminal and the Alexander Street intersection will also be shut down while construction continues. The commuter parking lot will stay as it is, while pedestrian paths to the temporary station will be slightly altered.

Monday night’s Council meeting also included introduction of an animal control ordinance, which will be given a public hearing at the next meeting on October 14. After much discussion about cost, the Council voted to retain the law firm of Miller, Porter & Muller for legal services surrounding the merging of land use codes, at a fee not to exceed $45,000.