{ "id": "2022-08-02-university-of-minnesota-petroleum-leak", "slug": "university-of-minnesota-petroleum-leak-2022-08-02", "institution": { "name": "University of Minnesota Twin Cities", "shortName": "UMN", "state": "MN", "type": "public-r1", "alertSystemName": "SAFE-U", "enrollment": 54000 }, "incident": { "date": "2022-08-02", "type": "hazmat", "cleryCategory": "emergency-notification", "resolution": "confirmed-threat", "headline": "Sewer petroleum vapors near the explosive limit force evacuation of six athletic buildings", "headlinePublic": "Sewer petroleum vapors near the explosive limit force evacuation of six athletic buildings", "summary": "On Tuesday morning, August 2, 2022, [Met Council contractors working in a sewer tunnel near 5th Street and Oak Street SE](https://www.mprnews.org/story/2022/08/02/petroleum-leak-evacuation-minnesota-twin-cities-campus-williams-arena) at the University of Minnesota Twin Cities reported their gas monitors had sounded an alarm and that they could see and smell petroleum in the tunnel. Some readings reached the lower explosive limit. Minneapolis Fire was on scene by approximately 11:30 AM CDT. UMN's [SAFE-U emergency notification system](https://publicsafety.umn.edu/safe-u-emergency-94) pushed evacuation orders covering Williams Arena, Huntington Bank Stadium, McNamara Alumni Center, the Aquatics Center, the Recreation and Wellness Center, and the Mariucci and Maturi Sports Pavilion. The Minnesota Department of Public Safety later determined the substance was diesel fuel. The [evacuation order was lifted at approximately 4:30 PM CDT](https://kstp.com/kstp-news/top-news/petroleum-leak-causes-evacuation-on-u-of-m-campus/).", "outcome": "Evacuation order lifted at approximately 4:30 PM CDT on August 2, 2022 after air and water quality readings returned to normal following sewer-system flushing. The Minnesota Department of Public Safety determined the substance was diesel fuel; the source of the spill remained unknown at the time of the all-clear. No injuries reported. This was the second major sewer-fuel evacuation on UMN's Twin Cities campus in 33 days, following the June 30, 2022 gasoline-sewer explosion that blew manhole covers off University Avenue.", "casualties": { "killed": 0, "injured": 0 } }, "alerts": [ { "sequence": 1, "type": "initial", "timestampApprox": "Late morning Tuesday, August 2, 2022 (approximately 11:30 AM CDT or shortly after, when Minneapolis Fire arrived and began coordinating evacuations)", "channel": "sms", "verbatimText": "U of M Twin Cities: Williams Arena being evacuated by orders of MFD for confirmed petroleum leak. All people are advised to stay clear of the area.", "isVerbatimConfirmed": true, "sourceUrl": "https://publicsafety.umn.edu/safe-u-emergency-90", "sourceDescription": "UMN SAFE-U Emergency (official)", "annotations": [ "Pushed late morning August 2, 2022, around the time Minneapolis Fire arrived at the Met Council sewer tunnel at 5th Street and Oak Street SE.", "SAFE-U's 'EMERGENCY' prefix is the system's highest-tier signal, distinct from the lower-tier SAFE-U Advisory used for crime alerts and weather watches." ], "characterCount": 147, "timestamp": "2022-08-02T11:51:55-05:00" }, { "sequence": 2, "type": "update", "timestamp": "2022-08-02T12:01:15-05:00", "channel": "sms", "verbatimText": "U of M Twin Cities: Williams Arena, Huntington Bank Stadium, McNamara, Aquatics Center, Recreation Center, Mariucci and Maturi Sports Pavilion being evacuated for gas odor based on Minneapolis Fire Department Assessment. All people are advised to stay clear of the area.", "isVerbatimConfirmed": true, "sourceUrl": "https://publicsafety.umn.edu/safe-u-emergency-89", "sourceDescription": "UMN SAFE-U Emergency (official)", "characterCount": 270, "annotations": [ "Recovered from official SAFE-U emergency archive page 89" ] }, { "sequence": 3, "type": "update", "timestampApprox": "Early Tuesday afternoon, August 2, 2022, as Minneapolis Fire continued to ventilate the sewer system", "channel": "sms", "verbatimText": "U of M Twin Cities: Update: Stay out of designated area. Minneapolis Fire Department considers the levels of petroleum hazardous. Evacuated buildings: Williams Arena, Huntington Bank Stadium, McNamara, Aquatics Center, Recreation Center, Mariucci Arena, and Maturi Sports Pavilion. updates and safety tips at z.umn.edu/alerts", "isVerbatimConfirmed": true, "sourceUrl": "https://publicsafety.umn.edu/safe-u-emergency-88", "sourceDescription": "UMN SAFE-U Emergency (official)", "annotations": [ "Minneapolis Fire ultimately washed out the sewer line to flush the petroleum, the same mitigation technique they had used 33 days earlier after the June 30, 2022 sewer-gasoline explosion that blew manhole covers across University Avenue.", "Some petroleum-vapor readings in the tunnel reached the 'lower explosive limit,' the lowest concentration at which the vapor will burn in air, meaning a brief window during which the sewer system could have ignited a second time." ], "characterCount": 325, "timestamp": "2022-08-02T13:21:35-05:00" }, { "sequence": 4, "type": "update", "timestamp": "2022-08-02T15:15:35-05:00", "channel": "sms", "verbatimText": "U of M Twin Cities: Update: Based on continued high gas levels in evacuated areas, employees who have been evacuated may end their work day and leave campus if they haven’t done so already. UMPD can assist with vehicle access upon request at parking structures in evacuated areas, which will be maintained until Mpls Fire provides all clear. Updates and safety tips at z.umn.edu/alerts", "isVerbatimConfirmed": true, "sourceUrl": "https://publicsafety.umn.edu/safe-u-emergency-87", "sourceDescription": "UMN SAFE-U Emergency (official)", "characterCount": 385, "annotations": [ "Recovered from official SAFE-U emergency archive page 87" ] }, { "sequence": 5, "type": "all-clear", "timestampApprox": "Approximately 4:30 PM CDT on Tuesday, August 2, 2022, after sewer flushing brought air and water quality back to normal", "channel": "sms", "verbatimText": "U of M Twin Cities: Update on the gas leak: Minneapolis Fire has provided the all clear to reopen University facilities evacuated earlier today. Some streets on or near campus may still experience traffic impacts as public works authorities continue to monitor the situation, so anticipate emergency personnel and others will still be present into the evening. Specifically, University Ave SE and 4th St SE remain closed to vehicles between 10th Ave SE and Oak St SE until this work is complete. Continue to be aware. If you smell a gas odor, call 612-624-COPS (2677). No further updates are planned unless circumstances change.", "isVerbatimConfirmed": true, "sourceUrl": "https://publicsafety.umn.edu/safe-u-emergency-85", "sourceDescription": "UMN SAFE-U Emergency (official)", "annotations": [ "The Minnesota Department of Public Safety later identified the substance as diesel fuel; the source of the spill remained unknown at the time of the all-clear.", "End-to-end evacuation lasted approximately five hours, from late-morning notification through the 4:30 PM all-clear." ], "characterCount": 628, "timestamp": "2022-08-02T16:51:15-05:00" } ], "sources": [ { "title": "Petroleum leak forces evacuations on U Twin Cities campus (MPR News)", "url": "https://www.mprnews.org/story/2022/08/02/petroleum-leak-evacuation-minnesota-twin-cities-campus-williams-arena", "type": "local-media" }, { "title": "Evacuation orders near U of M lifted as gas levels return to normal (KSTP)", "url": "https://kstp.com/kstp-news/top-news/petroleum-leak-causes-evacuation-on-u-of-m-campus/", "type": "local-media" }, { "title": "Evacuation order lifted on UMN campus following petroleum leak (CBS Minnesota)", "url": "https://www.cbsnews.com/minnesota/news/minneapolis-fire-crews-respond-to-possible-petroleum-leak-in-sewers-on-umn-campus/", "type": "local-media" }, { "title": "University of Minnesota evacuation orders lifted after gas spill (KARE 11)", "url": "https://www.kare11.com/article/news/local/williams-arena-university-of-minnesota-evacuated-due-to-gas-leak/89-a26dd7db-97db-45eb-b41f-aea2fe50b78b", "type": "local-media" }, { "title": "BREAKING: Confirmed petroleum leak, firefighters evacuate UMN buildings (The Minnesota Daily)", "url": "https://mndaily.com/273236/city/breaking-confirmed-petroleum-leak-firefighters-evacuate-umn-buildings/", "type": "student-newspaper" }, { "title": "Evacuation orders lifted after gasoline leak at University of Minnesota athletic sites (Star Tribune)", "url": "https://www.startribune.com/suspected-gasoline-leak-prompts-evacuation-of-several-university-of-minnesota-athletic-facilities/600195046", "type": "local-media" }, { "title": "Twin Cities Campus: SAFE-U Emergency (UMN Safe Campus)", "url": "https://safe-campus.umn.edu/news/twin-cities-campus-safe-u-emergency", "type": "official-archive" }, { "title": "SAFE-U EMERGENCY (UMN Department of Public Safety)", "url": "https://publicsafety.umn.edu/safe-u-emergency-94", "type": "official-archive" }, { "title": "UMN SAFE-U Emergency (official)", "url": "https://publicsafety.umn.edu/safe-u-emergency-90", "type": "official-archive" }, { "title": "UMN SAFE-U Emergency (official)", "url": "https://publicsafety.umn.edu/safe-u-emergency-88", "type": "official-archive" }, { "title": "UMN SAFE-U Emergency (official)", "url": "https://publicsafety.umn.edu/safe-u-emergency-85", "type": "official-archive" }, { "title": "UMN SAFE-U Emergency 89", "url": "https://publicsafety.umn.edu/safe-u-emergency-89", "type": "official-archive" }, { "title": "UMN SAFE-U Emergency 87", "url": "https://publicsafety.umn.edu/safe-u-emergency-87", "type": "official-archive" } ], "context": "On the late morning of Tuesday, August 2, 2022, [Met Council contractors working in the sewer tunnel](https://www.mprnews.org/story/2022/08/02/petroleum-leak-evacuation-minnesota-twin-cities-campus-williams-arena) located at 5th Street and Oak Street SE on the University of Minnesota Twin Cities campus reported their gas monitors had sounded an alarm and that they could see and smell petroleum in the tunnel, some readings reached the lower explosive limit. Minneapolis Fire was on scene by approximately 11:30 AM CDT. UMN's [SAFE-U emergency notification system](https://publicsafety.umn.edu/safe-u-emergency-94) pushed evacuation orders covering an unusually large athletic-facility footprint: [Williams Arena, Huntington Bank Stadium, McNamara Alumni Center, the Aquatics Center, the Recreation and Wellness Center, and the Mariucci and Maturi Sports Pavilion](https://mndaily.com/273236/city/breaking-confirmed-petroleum-leak-firefighters-evacuate-umn-buildings/). The [Minnesota Department of Public Safety later determined the substance was diesel fuel](https://kstp.com/kstp-news/top-news/petroleum-leak-causes-evacuation-on-u-of-m-campus/), though the source of the spill remained unknown. Fire crews flushed the sewer system, and the evacuation order was lifted at approximately 4:30 PM CDT after readings returned to normal. This incident occurred just 33 days after the [June 30, 2022 sewer-gasoline explosion](https://www.fox9.com/news/buildings-evacuated-near-university-of-minnesota-after-explosion) that blew manhole covers off University Avenue near a Delta Tau Delta fraternity-house fire, making the August 2 evacuation the second major sewer-fuel incident on UMN's Twin Cities campus in just over a month, prompting renewed questions about whether the two events shared a single underlying source of fuel entering the campus sewer system.", "keyFindings": [ "SAFE-U's evacuation push covered an unusually large athletic-facility footprint (six major buildings including Williams Arena and Huntington Bank Stadium) during a single coordinated emergency.", "The August 2 diesel-fuel evacuation came just 33 days after UMN's June 30 sewer-gasoline explosion, the second time in five weeks that petroleum vapors in campus sewer lines reached dangerous concentrations.", "Sewer-tunnel vapor readings reached the lower explosive limit, meaning a brief window during which a single ignition source could have triggered a second sewer-system explosion in five weeks." ], "responseTimeMinutes": null, "confidence": "high", "tags": [ "Minnesota", "University of Minnesota", "SAFE-U", "hazmat", "petroleum", "diesel-fuel", "sewer-leak", "athletic-facilities", "Big-Ten", "Williams-Arena", "Huntington-Bank-Stadium" ], "dateAdded": "2026-05-13", "lastUpdated": "2026-07-18", "addedBy": "ingestion" }