A Lawrence school district maintenance worker suffered a medical emergency Tuesday afternoon, which apparently caused a district vehicle to strike a small tree at the southeast corner of Sixth and Maine streets, district officials said.

Emergency workers performed cardiopulmonary resuscitation at the scene on the man, said Tom Bracciano, the district’s division director of operations and facility planning. He was taken to Lawrence Memorial Hospital, where he is in critical condition, Bracciano said.

Lawrence police spokeswoman Kim Murphree said the wreck happened at 3:38 p.m. The man’s injuries did not result from the collision, she said. The driver was traveling east in the center turn lane, and the van came to rest against a curb and a small tree, she said.