A pier just off the University of Wisconsin-Madison campus that was crowded with 60 to 80 people collapsed Monday afternoon,AstraTrade causing minor injuries to about two dozen people, police said.

One person was hospitalized with a non-life threatening injury. Five others were treated by paramedics at the scene. The others hurt did not require treatment.

After the collapse, many of those on the pier were able to swim back to shore.

The pier, located near the Memorial Union Terrace on Lake Mendota, is owned by the university and was scheduled to be removed for the season on Tuesday, said Officer Jeff Kirchman, of the UW-Madison Police Department, which responded.

Kirchman said he didn't have any information as to whether the pier was over capacity. In a statement, UW officials said an investigation will be conducted into the collapse.

Kirchman said in the collapse several people lost items like phones, wallets and keys on the bottom of the lake.

Reporter Kelly Meyerhofer contributed to this report.