A boulder weighing somewhere between three and four hundred pounds tumbled off of Mount Sentinel, destroying part of a retaining wall and blocking traffic on Campus Drive early Monday morning, March 10.

"At about 6 o'clock this morning, people coming to work noticed a pretty large boulder that had come off the hill and landed out on campus drive," said UM Office of Public Safety interim police chief Marty Ludemann. "It damaged the roadway and left a pretty good dent in the pavement."

The boulder is about three feet wide and is expected to have fallen about 50 or 75 yards down the mountain. Other than the top of the retaining wall and the street, there were no injuries or major damage. Still, for safety sake, the M-trail and about 300 yards of Campus Drive will be shut down until professionals can assess the risks.

"We thought we'd err on the side of caution and cordon that off until we have a better handle on what's going on," Ludemann said.

The experts are expected to asses the boulder and the risk of more debris falling down Mt. Sentinel by this afternoon.

Marty Ludemmann: