The accident appeared to have been caused by a structural failure, officials said.

After the first crash, the critics expressed little complaint since the accident appeared to have been a fluke.

Parks officials said the accident appeared to have occurred when she swerved to avoid some runners and was hit by the van.

He said the accident appeared to have been caused by excess speed.

The accident appears to have resulted from a lack proper maintenance and an investigation is under way.

Onlookers reported that Burke had completed a trick fairly well yet fell onto her head, and the accident did not appear to be very severe.

But other officials, speaking on condition of anonymity, said that yesterday's accident appeared to be a mechanical problem involving the track and the switches.

But Tuesday's accident appeared to have none of the elements that usually conspire to cause a derailment.

The accident appeared at least to have acted as a catalyst in the suicide, he said.

The accident appears to have occurred on or near a concrete and metal bridge over a frozen river in the park.