Officials in Washington County are joining Saint Paul in issuing a public safety alert due to a spike in drug overdoses. The Washington County Sheriff’s Office says it could be caused by potent heroin or other narcotics mixed with fentanyl, a deadly synthetic opioid. They say four people in Washington County have died in the last two weeks of suspected overdoses — two of those within the past 24 hours. And they say nalaxone was also used four times over the past two weeks to revive those suffering from potential overdoses. In Saint Paul, officials report five overdoses in a period of 36 hours earlier this week.