WIMBERLEY, Texas — A handful of volunteers trudged along the muddy and brush-filled banks of the Blanco River in Central Texas, searching for a group of people still missing days after the vacation house where they were staying was swept away in a massive flood.

A soggy teddy bear caught in a tree provided a stark reminder that children were among the missing. The volunteers, led by Toby Baker, a commissioner with Texas Commission on Environmental Quality, marked where the bear was found. They talked about the pajamas the children were wearing the night the river crested.

Baker had come in an unofficial capacity, as a childhood friend of one of the missing. “I’ve got a young family,” he said Friday. “I’d like to think someone would come out and do the same for us.”

At least 28 people have been killed in storms that began pummeling Texas and Oklahoma over Memorial Day weekend. Twenty-four of the deaths have been in Texas alone, and 11 people were still missing early Saturday. Rivers and lakes around Houston, San Antonio and Dallas have all swelled — and the flooding may not let up, with forecasters predicting more rain this weekend.

A church in Wimberly, a small tourist town about 20 miles northwest from where Baker’s group was working, has become a meeting spot for volunteers who’ve come to help look for the missing in that area.

About 2,000 volunteers have come through this week, and 100 members of an elite search and rescue team have been deployed to the area. Rescue dog teams walked about and a helicopter used the church lawn to take off and land.