Three people were stabbed during a late-night scuffle outside Denver’s football stadium after the Broncos lost 27-20 to the San Diego Chargers on Thursday night, according to a CNN report. One of the victims is in critical condition, and police have three people in custody. A fourth person may have been injured in the incident in the parking lot next to Sports Authority Field at Mile High. That person left without seeking treatment.

The other two known victims are in stable condition, according to police. It was not clear what started the 10 p.m. incident, but this is the second violent incident after a Broncos game this month. On December 1, a 30-year-old man died after he fought another person in a parking lot near the Kansas City Chiefs’ Arrowhead Stadium.